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Part 8: Appendixes > Glossary

Appendix A. Glossary

accelerator key

A key combination that provides access to a menu choice, macro, or other function of the application in lieu of a mouse click, usually by combining Alt+key. An accelerator key is identified on menus by an underlined character. It is sometimes (incorrectly) called a shortcut key, but shortcut keys usually consist of Ctrl+key combinations.

Access Control List (ACL)

Part of Windows NT's security description that controls access to a Windows NT object, such as a file. An object's owner can change access control entries in the list to grant or revoke permissions (access rights) for the object.

Access Developer's Toolkit

See [ADT]
Access SQL

The dialect of ANSI SQL used to write queries in all versions of Microsoft Access. For the most part, Access SQL complies with ANSI SQL-92. Access SQL offers additional features, such as the capability to include user-defined functions within queries.

access token

A Windows NT object that identifies a logged-on (authenticated) user. The access token contains the user's security ID (SID), the groups to which the user belongs, and other security information.

See also [SID]


An OLE 2.0 term meaning to place an object in a running state, which includes binding the object, or to invoke a method of the object.

See also [binding]


In Windows, the currently running application or the window to which user input is directed; the window with the focus.

See also [focus]


A Microsoft video technology that provides synchronized images and sound under Windows 95 and Windows NT 4.0, intended as a replacement for 32-bit Video for Windows.


A Microsoft trademark for a collection of technologies based on the Common Object Model (COM) and Distributed Common Object Model (DCOM).

See also [COM]
See also [DCOM]

ActiveX components

A replacement term for OLE Automation miniservers and in-process servers, also called Automation servers..

See also [OLE Automation]

ActiveX controls

Insertable objects supplied in the form of OCX files that, in addition to offering a collection of properties and methods, also fire events. ActiveX controls are lightweight versions of OLE Controls that also use the .ocx file extension.

See also [OLE Control]

ActiveX data objects

High-level data objects, similar in concept to Access 97's Data Access Object (DAO) and Remote Data Object (RDO), that use Microsoft's new OLE DB (OLE Database) technology to access data from a variety of data sources, including text files and mainframe databases.

See also [OLE DB]

ActiveX documents

Files that can be inserted into the Microsoft Binder, such as files created by Microsoft Excel 7+ and Word 7+, as well as displayed in their native format in Internet Explorer 3+. ActiveX documents originally were called Document Objects or DocObjects.

ActiveX scripting

Another name for Visual Basic, Scripting Edition (VBScript), a simplified version of VBA designed for client-side automation of Web pages.

ActiveX server framework

ActiveX scripting for creating server-side Internet and intranet applications. Unlike ActiveX scripting, the ActiveX Server Framework (code-named Denali) allows file and other low-level operations.


A wizard (such as the Query Wizard) or builder (such as the Menu Builder) that helps Access users create or run database applications. You use Access 97's Add-In Manager to install wizards and builders (choose Tools, Add-Ins).

See also [builder]


The numerical value, usually in hexadecimal format, of a particular location in your computer's random-access memory (RAM).


Acronym for the Access Developer's Toolkit for Access 2.0 and Access 95 that allowed distribution of files needed to run (but not design) Access 2.0 and Access 95 applications. For Access 97, the ADT is replaced by the Office 97 Developer Edition (ODE), which provides the same features as the Access 95 ADT, plus developer products for other Office applications.

See also [ODE]

aggregate functions

The ANSI SQL functions AVG(), SUM(), MIN(), MAX(), and COUNT(), and Access SQL functions StDev(), Var(), First(), and Last(). Aggregate functions calculate summary values from a group of values in a specified column and are usually associated with GROUP BY and HAVING clauses.

See also [domain aggregate functions]

aggregate object

An OLE 2.0 term that refers to an object class that contains one or more member objects of another class.


A temporary name assigned by Access to a table in a self join, to a column of a query, or to rename a table, implemented by the AS reserved word in ANSI SQL. You can use AS to rename any field or table with Jet SQL. Alias is also an embedded keyword option for the VBA Declare statement. The Alias keyword is used to register prototypes of DLL functions so that the function can be called from programs by another name. Aliasing the ANSI versions of 32-bit Windows API functions to function names without the A suffix is common when converting Access 1.x and 2.0 applications to Access 97, which uses Unicode strings.


An acronym for the American National Standards Institute. ANSI in the Windows context refers to the ANSI character set that Microsoft decided to use for Windows (rather than the IBM PC character set that includes special characters such as those used for line drawing, called the OEM character set). The most common character set is ASCII (American Standard Code for Information Interchange), which for English alphabetic and numeric characters is the same as ANSI. Windows 95 and Windows NT include ANSI (suffix A) and Unicode (suffix W) versions of Windows API functions.

See also [ASCII]
See also [Unicode]


An acronym for Application Programming Interface. Generically, a method by which a program can obtain access to or modify the operating system. In 32-bit Windows, the 1,000 or so functions provided by Windows 95 and Windows NT DLLs that allow applications to open and close windows, read the keyboard, interpret mouse movements, and so on. Programmers call these functions hooks to Windows. VBA provides access to these functions with the Declare statement.

See also [DLL]


A Windows application that is supplied as a component of another Windows application, rather than a retail product. The Notepad, WordPad, and Character Map applications supplied with Windows 95 are examples of applets.


The software product that results from the creation of a program, often used as a synonym for the programming (source) code that creates it. Microsoft Word, Microsoft Excel, WordPerfect for Windows, and Lotus 1-2-3 are called mainstream Windows productivity applications in this book. Applications are distinguished by the environment for which they are designed (such as Windows, DOS, Macintosh, and UNIX) and their purpose. Windows applications carry the DOS executable file extension, .exe.

application Close button

The small, square button with an x caption at the extreme right of the title bar of an application running in Windows 95. Clicking the Application Close button closes the running application.

application Control-menu box

The small square button with a miniature application icon at the extreme left of the title bar of an application. Clicking the application Control-menu box displays the application Control menu. Double-clicking the application Control-menu box closes the application.


Data supplied to a function and on which the function acts or uses to perform its task. Arguments are enclosed in parentheses. Additional arguments, if any, are separated by commas. Arguments passed to procedures usually are called parameters.


An ordered sequence of values (elements) stored within a single named variable, accessed by referring to the variable name with the number of the element (index or subscript) in parentheses, as in strValue = strArray(3). VBA arrays may have more than one dimension, in which case access to the value includes indexes for each dimension, as in strValue = strArray(3,3).


Acronym for the American Standard Code for Information Interchange. A set of standard numerical values for printable, control, and special characters used by PCs and most other computers. Other commonly used codes for character sets are ANSI (used by Windows 3.1+), Unicode (used by Windows 95 and Windows NT), and EBCDIC (Extended Binary-Coded Decimal Interchange Code, used by IBM for mainframe computers).

See also [Unicode]


To give a value to a named variable.


A process that can occur at any time, regardless of the status of the operating system or running applications.

attached table

A table that is not stored in the currently open Access database (native or base table), but which you can manipulate as if the table were a native table. In Access 95 terminology, an attached table is a linked table.

See also [linked table]


The process of verifying a user's login ID and password.


An ActiveX and OLE 2.0 term that refers to a means of manipulating another application's objects.

See also [OLE Automation]

automation client

An ActiveX- or OLE 2-compliant Windows application with an application programming (macro) language, such as VBA, that can reference and manipulate objects exposed by (OLE) Automation servers.

automation server

Technically, any COM- or OLE 2-compliant Windows application that supports Automation operations by exposing a set of objects for manipulation by Automation client applications. This book restricts the term automation server to applications that are not OLE 2+ full servers, but expose application objects. Access 97 is an example of an automation server.


An Access 95 replacement for the Counter field data type of Access 1.x and 2.0. AutoNumber fields may be of the Increment or Random type. Fields of the Increment AutoNumber field data type usually are used to create primary keys in cases where a unique primary key cannot be created from data in the table.


A feature of Windows 95's and Windows NT 4.0's CD-ROM file system (CDFS) that automatically executes a program on the CD-ROM when inserted into the CD-ROM drive.

back up

To create a file (backup file) that duplicates data stored in one or more files on a client or server computer.


In multitasking computer operations, the application or procedure that is not visible on-screen and that does not receive user-generated input. In Windows, a minimized application that does not have the focus is in the background.

base date

A date used as a reference from which other date values are calculated. In the case of VBA and SQL Server, the base date is January 1, 1900.

base tables

The permanent tables from which a query is created. A synonym for underlying tables. Each base table in a database is identified by a name unique to the database. Access also uses the term base table to refer to a table in the current database in contrast to a linked (attached) table.

See also [linked table]


A group of statements processed as an entity. Execution of DOS batch files, such as AUTOEXEC.BAT, and SQL statements are examples of batch processes.


An abbreviation for Backup Domain Controller, a Windows NT server that provides an alternative source of authentication for network users. Account and group information from a Primary Domain Controller (PDC) is replicated periodically to each BDC in the domain.

See also [PDC]

binary file

A file whose content does not consist of lines of text. Executable (.exe), dynamic link library (.dll), and most database files are stored in binary format.

binary string

A string consisting of binary, not text, data that contains bytes outside the range of ANSI or ASCII values for printable characters. Access 97 requires that you store binary strings as arrays of the Byte data type to avoid problems with Unicode/ANSI conversion.


In Access, attaching a Form or Report object to a table, or attaching a control object to a table field or the column of a query result set. The bound Form or Report object determines the current record of the table or the bound control object reflects the value of the data cell or field of the current record or row.


The smallest piece of information processed by a computer. A bit, derived from the contraction of BInary digiT (or Binary digIT) has two states: on (1) or off (0). Eight bits make up a byte, and 16 bits combined is called a word.


The representation of a screen or printed image, usually graphic, as a series of bytes.


A process that evaluates each bit of a combination, such as a byte or word, rather than processes the combination as a single element. Logical operations and masks use bitwise procedures.


The process of using the BitBlt() function of the Windows Gdi32. exe file to modify a bitmap by using bit block transfer.


A type of arithmetic in which all digits are bits—that is, the numbers may have only two states: on (true or 1) or off (false or 0). Widely used in set theory and computer programming, Boolean, named after the mathematician George Boole, also is used to describe a VBA data type that may have only two states: true or false. In VBA, true is represented by &HFF (all bits of an 8-bit byte set to 1) and false by &H0 (all bits set to 0).


See also [binding]
See also [object frame]


To cause an interruption in program operation. Ctrl+C, the standard DOS break key combination, seldom halts operation of a Windows application. Esc is more commonly used in Windows to cause an operation to terminate prior to completion.


A designated statement that causes program execution to halt after executing the statement preceding it. To toggle breakpoints on or off, choose Run, Toggle Breakpoint in Access, or press the F9 function key.


An acronym for Basic Rate Interface, the standard ISDN service for business and residential Internet connections. BRI has two 56 kbps B (bearer) channels and one 16 kbps D (data) channel, providing a maximum bandwidth of 112 kbps.

See also [ISDN]

Briefcase replication

A feature of Access 97 running under Windows 95 that permits the creation of Access replication sets stored in Windows 95 Briefcase folders, which can be updated by mobile users. Subsequently, the briefcase replicates are used to update the design-master replica to synchronize the design-master replica with the contents of the briefcase replicas.

See also [design-master replica]


An area in memory of a designated size (number of bytes or characters) reserved, typically, to hold a portion of a file or the value of a variable. When string variables are passed as arguments of DLL functions, you must create a buffer of sufficient size to hold the returned string. This is accomplished by creating a fixed-length string variable of the necessary size, using the String() function, prior to calling the DLL function.


A component of Access that provides assistance in creating expressions (Expression Builder) or controlling objects.

built-in functions

Functions that are included in a computer language and don't need to be created by the programmer as user-defined functions.

business rules

A set of rules for entering data in a database that are specific to an enterprise's method of conducting its operations. Business rules are in addition to rules for maintaining the domain and referential integrity of tables in a database. Business rules most commonly are implemented in a three-tier client/server database environment.

See also [three-tier]


A block of memory reserved for temporary storage. Caches usually store data from disk files in memory to speed access to the data. By default, Windows 95 caches all disk read and write operations.


The title that appears in the title bar of a window. Access calls the text of a label, check box, frame, and command or option button control object the Caption property.


The term used by Windows to indicate the cursor used when editing a text field, usually shaped as an I-beam. The caret, also called the insertion point, can be positioned independently of the mouse pointer.

Cartesian product

Named for René Descartes, a French mathematician. Used in JOIN operations to describe all possible combinations of rows and columns from each table in a database. The number of rows in a Cartesian product is equal to the number of rows in table 1 times that in table 2 times that in table 3, and so on. Cartesian rows that do not satisfy the JOIN condition are disregarded.

cascading deletion

A trigger that deletes data from one table based on a deletion from another table to maintain referential integrity. Usually used to delete detail data (such as invoice items) when the master record (invoice) is deleted. Access 2+ provides cascading deletion as an optional component of its referential integrity features.

See also [referential integrity]

case sensitivity

A term used to define whether the interpreter or compiler treats lowercase and uppercase letters as the same character. Most are case-insensitive. C is an exception; it is case-sensitive, and all its keywords are lowercase. Many interpreters, including VBA, reformat keywords to its standard: a combination of uppercase and lowercase letters. VBA does not distinguish between uppercase and lowercase letters used as names for variables.


The 32-bit CD-ROM file system shared by Windows NT and Windows 95.


In Windows, ordinarily refers to a unique task ID assigned to a dynamic data exchange (DDE) conversation. Channel IDs are Long integers under Windows 95 and Windows NT. Also used to identify an I/O port in mini- and mainframe computers.

check box

A Windows dialog and Access control object that consists of a square box and an associated caption. An x or other mark in the box is created or erased (toggled) by alternate clicks on the box or the label with the mouse or by pressing an assigned hotkey.


In Windows, usually a shortened form of MDI child window. Also used in computer programming in general to describe an object that is related to but lower in hierarchical level than a parent object.


A part of a RIFF or standard MIDI file that is assigned to a particular function and may be treated as a single element by an application. VBA uses the term chunk to refer to a part of any file that you read or write with the GetChunk and AppendChunk methods.

See also [RIFF]

class identifier


The portion of a SQL statement beginning with a keyword that names a basic operation to be performed.


The device or application that receives data from or manipulates a server device or application. The data may be in the form of a file received from a network file server, an object from an ActiveX component or OLE server, or values from a DDE server assigned to client variables.

See also [automation client]


Windows' temporary storage location for text and graphic objects, as well as Access objects, such as control objects, forms, tables, reports, and so on. The Clipboard is the intermediary in all copy, cut, and paste operations. You can view and save the contents of the Clipboard by using Program Manager's Clipboard applet.


An identification tag that is associated with an OLE 2.0 object created by a specific server. CLSID values appear in the Registry and must be unique for each ActiveX component or OLE 2.0 server and each type of object that the server can create.

See also [Registry]

clustered index

An index in which the physical record order and index order of a table are the same.


A server architecture that emulates multiprocessing by interconnecting two or more individual computers to share the application processing load. Microsoft's future clustering technology for Windows NT now carries the code name Wolfpack. A number of third parties offer proprietary clustering hardware and software for Windows NT Server 4.0.


Short for source code, the text you enter in your program to create an application. Code consists of instructions and their parameters, functions and their arguments, objects and their events, properties and methods, constants, variable declarations and assignments, and expressions and comments.

code template

Self-contained groups of modules and resources that perform a group of standard functions and that may be incorporated within other applications requiring these functions, usually with little or no modification.

Code window

In Access, the window that appears when you select Module from the Database window or click the ... button of an event property to create or edit an event-handling subprocedure. Also called the code-editing window.


The process of forcing a change from one data type to another, such as Integer to Text.


A group of objects of the same class that are contained within another object. Collections are named as the plural of their object class. As an example, the Forms and Reports collections are groups of Form and Report objects contained in the Database object.

color palette

A means of establishing a foreground or background color in Windows by selecting a color from those displayed with the mouse. The color palette then converts the selection to the standard Windows RGB (red/green/blue) color format. The color palette provides the set of colors for graphic objects of 256 colors or less. Access 2+ allows you to specify a particular palette for individual forms. Also called palette or Windows palette.


An acronym for Component Object Model, the name of Microsoft's design strategy to implement ActiveX and OLE 2+. Distributed COM (DCOM) allows networked and cross-platform implementation of ActiveX and OLE 2+ operations and (OLE) Automation.

See also [DCOM]

combo list

A Windows object that combines text box and list elements into a single object. In Access, combo lists are of the drop-down type by default. The list element of a drop-down combo list appears when a downward-pointing arrow to the right of the text box is clicked.


A synonym for instruction. Specifies an action to be taken by the computer.

command button

A Windows object that causes an event when clicked. Command buttons are ordinarily a gray rectangle containing a caption and surrounded by a border.


Explanatory material within source code not designed to be interpreted or compiled into the final application. In VBA, comments are usually preceded by an apostrophe (') but can also be created by preceding them with the Rem keyword.

common dialog

A standardized dialog, provided by Windows 95 and Windows NT, that may be created by a Windows API function call to functions contained in Cmdlg32.dll. Common dialogs include FileOpen, FileSave, Print and Printer Setup, ColorPalette, Font, and Search and Replace. Using the common dialogs in Access applications requires that you use the Declare statement to create function prototypes for the functions in Comdlg32.dll that you plan to use. The Comdlg32.ocx control, included with the Office 97 Developer Edition, lets you implement most of the common dialogs without needing to call Comdlg32.dll functions.

Common User Access

See also [CUA]

comparison operators

See also [operator]


To create an executable or object (machine-language) file from source (readable) code. In Access, compile means to create pseudo-code (tokenized code) from the VBA source code you write in the code-editing window.

Component Object Model

See also [COM]

composite key or index

A key or index based on the values in two or more columns.

See also [index]
See also [key or key field]
See also [key or key field]

composite menu

A menu that includes menu choices from an OLE 2.0 server application that uses in-place (in-situ) activation (editing). Creating a composite menu also is called grafting a menu.

composite moniker

The location within a container document or object where the compound document is located.


In computer programming, a set of instructions or statements that requires more than one keyword or group of related keywords to complete. Select Case...Case...End Select is an example of a compound statement in VBA.

compound document

A document that contains OLE objects created by an application other than the application that originally created or is managing the document.


Combining two expressions, usually strings, to form a longer expression. The concatenation operator is & in SQL and VBA, although VBA also permits the + symbol to be used to concatenate strings.


The condition when more than one user has access to a specific set of records or files at the same time. Also used to describe the ability of a database management system to handle simultaneous queries against a single set of tables.


An object or application that can create or manipulate compound documents.

context switching

The process of saving an executing thread or process and transferring control to another thread or process. Windows NT 4.0's context switching—one of the major bottlenecks in COM operations—is substantially faster than in Window NT 3.x.


A synonym for a dialog object in Access. Controls include labels, text boxes, lists, combo lists, option buttons, and command buttons. Access 97 also provides compatibility with ActiveX Controls (formerly OLE Controls).

control array

In Visual Basic, the term given to multiple controls on a single form with the same Name property. (Access does not support control arrays.) Individual controls (elements) of a control array are designated by their index, starting with 0, up to one less than the number of controls with the same name.

Control menu box

See also [application Control-menu box]
See also [document Control menu box]


In DDE operations, the collection of Windows messages that are passed between two different applications—the client and server—during an interprocess communication.

correlated subquery

A subquery that cannot be independently evaluated. Subqueries depend on an outer query for their result.

See also [subquery]
See also [nested query]


A special field data type of Access 1.x and 2.0 tables that numbers each new record consecutively; called an AutoNumber field in Access 95 and 97.

See also [AutoNumber]


An abbreviation for Common User Access, an element of IBM's SAA (Systems Application Architecture) specification, which establishes a set of standards for user interaction with menus, dialogs, and other user-interactive portions of an application. The CUA was first implemented in Windows and OS/2 and has been an integral part of these GUIs since their inception.

current database

The database opened in Access by choosing F ile, Open Database (or the equivalent) that contains the objects of an Access application.

current record

The record in a Table or Recordset object whose values you modify. The current record supplies values of the current record's data cells to control objects that are bound to the table's fields.

current statement

The statement or instruction being executed at a particular instance in time. In debugging or stepwise operation of interpreted applications such as Access, the current statement is the next statement that will be executed by the interpreter when program operation is resumed.

custom control

The former name for a control object not native to the application. Access 97 supports 32-bit ActiveX and OLE controls (OCXs). Visual Basic 3.0 and Visual C++ 3.0 use 16-bit Visual Basic Extension custom controls (VBXs). Visual Basic 4.0 supports 16-bit VBXs and OCXs, plus 32-bit OCXs.

See also [ActiveX controls]
See also [OLE Control]

data access object

The container for all the objects that can be embodied in an Access application, often abbreviated DAO. The top member of the data access object hierarchy of Access is the DBEngine object, which contains Workspace, User, and Group objects in collections. Database objects are contained in Workspace objects.

See also [ActiveX data objects]

data definition

The process of describing databases and database objects such as tables, indexes, views, procedures, rules, default values, triggers, and other characteristics.

data dictionary

The result of the data definition process. Also used to describe a set of database system tables that contain the data definitions of database objects, often called metadata.

data element

The value contained in a data cell, also called a data item or simply an element. A piece of data that describes a single property of a data entity, such as a person's first name, last name, Social Security number, age, sex, or hair color. In this case, the person is the data entity.

data entity

A distinguishable set of objects that is the subject of a data table and usually has at least one unique data element. A data entity might be a person (unique Social Security number), an invoice (unique invoice number), or a vehicle (unique vehicle ID number, because license plates are not necessarily unique across state lines).

data integrity

The maintenance of rules that prevent inadvertent or intentional modifications to the content of a database that would be deleterious to its accuracy or reliability.

See also [domain integrity]
See also [referential integrity]

data modification

Changing the content of one or more tables in a database. Data modification includes adding, deleting, or changing information with the INSERT, DELETE, and UPDATE SQL statements. Data modification often is called updating.

data sharing

The ability to allow more than one user to access information stored in a database from the same or a different application.

data type

The description of how the computer is to interpret a particular item of data. Data types are generally divided into two families: strings that usually have text or readable content, and numeric data. The types of numeric data supported vary with the compiler or interpreter used. Most programming languages support a user-defined record or structure data type that can contain multiple data types within it. Field data types, which define the data types of database tables, are distinguished from Access table data types in this book.


A set of related data tables and other database objects, such as a data dictionary, that are organized as a group.

database administrator

The individual(s) responsible for the administrative functions of client/server databases. The database administrator (DBA) has privileges (permissions) for all commands that may be executed by the RDBMS and is ordinarily responsible for maintaining system security, including access by users to the RDBMS itself and performing backup and restoration functions.

database device

A file in which databases and related information, such as transaction logs, are stored. Database devices usually have physical names (such as a file name) and a logical name (the parameter of the USE statement). In SQL Server, database devices use the .dat file extension.

database object

A component of a database. Database objects include tables, views, indexes, procedures, columns, rules, triggers, and defaults. The DBEngine object in Access VBA is the topmost member of the class of Access objects. All objects within a single database are subclasses of the Database object.

database owner

The user who originally created a database. The database owner has control over all the objects in the database but may delegate control to other users. Access calls the database owner the creator. The database owner is identified by the prefix dbo in SQL Server.

Database window

The window that appears when you open an Access database and lists the objects (tables, queries, forms, reports, macros, and modules) contained in the Database object.

date function

A function that provides date and time information or manipulates date and time values.


An acronym for Distributed Common Object Model. Allows communication and manipulation of objects over a network connection. Windows NT 4.0 is the first Microsoft operating system to support DCOM (formerly called NetworkOLE). Microsoft released a DCOM update for Windows 95 in mid-1997.

See also [COM]


An acronym for dynamic data exchange. A method used by Windows and OS/2 to transfer data between different applications. Automation (formerly OLE Automation) provides a more robust method for communication between applications or components of applications.


A condition that occurs when two users with a lock on one data item attempt to lock the other's data item. Most RDBMSs detect this condition, prevent its occurrence, and advise both users of the potential deadlock situation.


The act of removing errors in the source code for an application.

Debug window

A non-modal dialog in which you may enter VBA expressions and view results without writing code in a code-editing window. You may also direct information to be displayed in the Debug window with the Debug object. The appearance of the Debug window varies slightly between VBA-enabled applications.


A statement that creates a user-defined data type, names a variable, creates a symbolic constant, or registers the prototypes of functions incorporated within dynamic link libraries.

declaration section

A section of a VBA module reserved for statements containing declarations.


In text and not as a keyword, to create a user-defined data holder for a variable or constant. As a VBA keyword, to register a function contained in a dynamic link library in the declarations section of a module.


A value assigned or an option chosen when no value is specified by the user or assigned by a program statement.

default database

The logical name of the database assigned to a user when he or she logs in to the database application.

demand lock

Precludes more shared locks from being set on a data resource. Successive requests for shared locks must wait for the demand lock to be cleared.


A condition in which master data in a table (such as invoices) is associated with detail data in a subsidiary table (invoice items). In this case, invoice items are dependent on invoices.

design-master replica

The member of an Access replica set that allows changes in the design of objects, such as tables. The design-master replica usually (but not necess-arily) is the .mbd file that is updated by briefcase replicas of the file.

See also [Briefcase replication]

design mode

One of three modes of operation of Access, also called Design view. Design mode allows you to create and modify tables, queries, forms, reports, and control objects; enter macro actions; and write VBA code. The other two modes are run mode, also called runtime (when the application is executing), and startup mode (before you open an Access database).

destination document

A term used by OLE 1.0 to refer to a compound document.

detail data

Data in a subsidiary table that depends on data in a master table to have meaning or intrinsic value. If a user deletes the master invoice records, the subsidiary table's detail data for items included in the invoice lose their reference in the database—they become orphan data.

detail table

A table that depends on a master table. Detail tables usually have a many-to-one relationship with the master table.

See also [detail data]


A computer system component that can send or receive data, such as a keyboard, display, printer, disk drive, or modem. Windows uses device drivers to connect applications to devices.

device context

A record (struct) containing a complete definition of all variables required to fully describe a window containing a graphic object. These include the dimensions of the graphic area (viewport), drawing tools in use (pen, brush), fonts, colors, drawing mode, and so on. Windows provides a handle (hDC) for each device context.


Acronym for Dynamic Host Configuration Protocol, an Internet standard protocol that allows IP addresses to be pooled and assigned as needed to clients. Windows NT 4.0 includes DHCP Manager, a graphical DHCP configuration tool.

See also [IP]
See also [IP address]


A pop-up modal child window, also called a dialog box, that requests information from the user. Dialogs include message boxes, input boxes, and user-defined dialogs for applications, such as choosing files to open.


An acronym for Device-Independent Bitmap, a Windows-specific bitmap format designed to display graphic information. DIB files take the extension .dib and use a format similar to .bmp.


In data tables, data elements that are contained in one table but not in another.

directory list

An element of a file-selection dialog that selectively lists the subfolders of the designated folder of a specified logical drive.

disk mirroring

Creating on two or more physical disk drives exact duplicates of a disk volume to make files accessible in case of failure of one drive of the mirror set.

See also [RAID]

disk striping

Distributing the data for a single logical disk volume across two or more physical disk drives. Simple disk striping (RAID 0) provides faster I/O operation. Disk striping with parity (RAID 5) provides faster I/O and protection from failure of a physical disk in a stripe set.

See also [RAID]

distributed database

A database, usually of the client/server type, that is located on more than one database server, often at widely separated locations. Synchronization of data contained in distributed databases is most commonly accomplished by the two-phase commit or replication methods.

See also [replication]
See also [two-phase commit]


An acronym for dynamic link library, a file containing a collection of Windows functions designed to perform a specific class of operations. Most DLLs carry the .dll extension, but some Windows DLLs, such as Gdi32.exe, use the .exe extension. Functions within DLLs are called (invoked) by applications, as necessary, to perform the desired operation.


The file format for creating persistent OLE objects, now called ActiveX documents. Docfiles usually have the extension .ole. Fully OLE 2-compliant applications create docfiles with specific extensions, such as .doc (Word) and .xls (Excel). Access 95 .mdb files also are OLE 2 docfiles. OLE 2.1 requires that docfiles include file property values derived from choosing File, Properties.

See also [ActiveX documents]


A programming object that contains information that originates with the user of the application, rather than be created by the application itself. The data for documents usually is stored in disk files. Access tables, forms, and reports are documents, as are Excel or Lotus 1-2-3 worksheets. In Windows 95 and Windows NT 4.0, a document is a file with an association to an application that can display or manipulate the file.

document Control menu box

The small, square button at the upper-left corner of an application's menubar that uses the multiple document interface (MDI). Clicking the document Control-menu box displays the document Control menu. Double-clicking the document Control-menu box closes the document (but not the application).


A group of workstations and servers that share a common security account manager (SAM) database and that allow a user to log on to any resource in the domain with a single user ID and password. In Access, a domain is a set of records defined by a table or query.

See also [BDC]
See also [PDC]

domain aggregate functions

A set of functions, identical to the SQL aggregate functions, that you can apply to a specified domain, rather than to one or more Table objects.

See also [aggregate functions]

domain integrity

The process of assuring that values added to fields of a table comply with a set of rules for reasonableness and other constraints. As an example, domain integrity is violated if you enter a ship date value that is earlier than an order date. In Access, domain integrity is maintained by field-level and table-level validation rules.

See also [business rules]


A Windows process whereby you use the mouse to move (drag) an icon representing an object, such as a file, to another location (such as a different directory) and place (drop) it. You can use drag-and-drop techniques in Access 97's design mode. Access does not provide the same drag-and-drop capabilities for control objects that are available with Visual Basic.


The logical identifier of a disk drive, usually specified as a letter. When used as a component of a path, the drive letter must be followed by a colon and backslash, as in C:\.

dynamic data exchange

See also [DDE]

dynamic link library

See also [DLL]


A set of rows and columns in your computer's memory that represent the values in an attached table, a table with a filter applied, or a query result set. You can update the values of the fields of the underlying table(s) by changing the values of the data cells of an updatable Dynaset object. In Access 2+, Dynaset is a type of Recordset object.

See also [Recordset]

embedded object

A source document stored as an OLE object in a compound or container document.


A condition of a VBA variable that has been declared but has not been assigned a value. Empty is not the same as the Null value, nor is it equal to the empty or zero-length string ("").


The ability of a control object to respond to user actions such as a mouse click, expressed as the True or False value of the Enabled property of the control.


A combination of the computer hardware, operating system, and user interface. A complete statement of an environment follows: a 166 MHz Pentium computer with a VGA display and two-button mouse, using the Windows 95 operating system.

environmental variable

A DOS term for variables that are declared by PATH and SET statements (usually in an AUTOEXEC.BAT file) and stored in a reserved memory location by DOS. In Windows 95 and Windows NT, required environmental variables are stored in the Registry, although Windows 95 accepts environmental variables in the AUTOEXEC.BAT file for backward compatibility with 16-bit Windows applications. The environmental variables may be used by applications to adjust their operation for compatibility with user-specific hardware elements or folder structures.


A JOIN in which the values in the columns being joined are compared for equality and all columns in both tables are displayed. An equi-join causes two identical columns (both joined columns) to appear in the result.

error trapping

A procedure by which errors generated during the execution of an application are rerouted to a designated group of code lines (called an error handler) that performs a predefined operation, such as ignoring the error. If errors are not trapped in VBA, the standard modal message dialog with the text message for the error that occurred appears.


The occurrence of an action taken by the user and recognized by one of Access's event properties, such as On Click or On DblClick, corresponding to VBA's Click and DblClick event handlers. Events are usually related to mouse movements and keyboard actions; however, events also can be generated by code with the Timer control object.


The property of an operating system or environment, such as Windows, that implies the existence of an idle loop. When an event occurs, the idle loop is exited and event-handler code, specific to the event, is executed. After the event handler completes its operation, execution returns to the idle loop, awaiting the next event.

exclusive lock

A lock that prevents others from locking data items until the exclusive lock is cleared. Exclusive locks are placed on data items by update operations, such as SQL's INSERT, UPDATE, and DELETE. In Access and SQL Server, page locking is used; SQL Server 6.5 provides row locking for INSERT operations.


Code, usually in the form of a disk file, that can be run by the operating system in use to perform a particular set of functions. Executable files in Windows carry the extension .exe and may obtain assistance from dynamic link libraries (DLLs) in performing their tasks.


The second element of a number expressed in scientific notation, the power of 10 by which the first element, the mantissa, is multiplied to obtain the actual number. For +1.23E3, the exponent is 3, so you multiply 1.23 by 1,000 (10 to the third power) to obtain the result: 1,230.


A combination of variable names, values, functions, and operators that return a result, usually assigned to a variable name. Result = 1 + 1 is an expression that returns 2 to the variable named Result. DiffVar = LargeVar-SmallVar returns the difference between the two variables to DiffVar. Functions may be used in expressions, and the expression may return the value determined by the function to the same variable as that of the argument. strVar = Mid$ (strVar, 2, 3) replaces the value of strVar with three of its characters, starting at the second character.


A fault-tolerant clustering architecture in which two servers share a common set of fault-tolerant fixed disk drives. In the event of failure of one of the servers, the other transparently assumes all server processing operations.

See also [clustering]
See also [fault tolerance]


An acronym for file allocation table, the disk file system used by MS-DOS, Windows 95, and (optionally) Windows NT. Windows NT is compatible with the 16-bit FAT system but not the optional 32-bit FAT (FAT32) for Windows 95 that Microsoft announced in mid-1996.

See also [HPFS]
See also [NTFS]

fault tolerance

A computer system's capability to maintain operability, despite failure of a major hardware component such as a power supply, microprocessor, or fixed-disk drive. Fault tolerance requires redundant hardware and modifications to the operating system. Windows NT Server includes fault tolerance for a failed disk drive by disk mirroring (RAID 1) or disk striping with parity (RAID 5). Clustering provides fault tolerance for individual computers.

See also [clustering]
See also [RAID]


A lightweight thread, introduced in Windows NT 4.0, that makes it easier for developers to optimize scheduling within multithreaded applications.

See also [thread]


Synonym for a column that contains attribute values. Also, a single item of information in a record or row.

fifth normal form

The rule for relational databases that requires that a table that has been divided into multiple tables must be capable of being reconstructed to its exact original structure by one or more JOIN statements.


The logical equivalent of a table. In dBASE, for instance, each table is a single .dbf file.

file moniker

The location of the well-formed path to a persistent OLE 2+ object.

first normal form

The rule for relational databases that dictates that tables must be flat. Flat tables can contain only one data value set per row. Members of the data value set, called data cells, are contained in one column of the row and must have only one value.


A variable, usually Boolean (True/False), that is used to determine the status of a particular condition within an application. The term set is often used to indicate turning a flag from False to True, and reset for the reverse.

flow control

In general usage, conditional expressions that control the execution sequence of instructions or statements in the source code of an application. If...Then...End If is a flow-control statement.


The currently selected application, or one of its windows, to which all user-generated input (keyboard and mouse operations) is directed. The object with the focus is said to be the active object. The title bar of a window with the focus is colored blue for the default Windows color scheme.


A typeface in a single size, usually expressed in points, of a single style or having a common set of attributes. Font often is misused to indicate a typeface family or style.


In multitasking operations, the application or procedure that is visible on-screen and to which user-generated input is directed. In Windows, the application that has the focus is in the foreground.

foreign key

A column or combination of columns whose value must match a primary key in another table when joined with it. Foreign keys need not be unique for each record or row.

See also [primary key]


A synonym for a user-defined MDI child window in Access. A Form object contains the control objects that appear on its surface and the code associated with the events, methods, and properties applicable to the form and its control objects.


Variables that are declared in the Declarations section of an Access form. These variables are said to have form-level scope and are not visible to procedures outside the Form object in which the variables are declared, unless declared with the Public reserved word.

fourth normal form

The rule for relational databases that requires that only related data entities be included in a single table and that tables may not contain data related to more than one data entity when many-to-one relationships exist among the entities.


In Windows, a rectangle, usually with a single-pixel-wide border, that encloses a group of objects, usually of the dialog class. When referring to SMPTE timing with MIDI files, a frame is one image of a motion picture film (1/24 seconds) or one complete occurrence of a television image (approximately 1/30 second in NTSC, 1/25 second in PAL).

front end

When used with database management systems, an application, window, or set of windows by which the user may access and view database records, as well as add to or edit them.

full server

An OLE 2-compliant executable application that can provide embeddable or linked documents for insertion into OLE 2+ container documents. Excel 95, Word 95, Project 4.1, and Wordpad are examples of OLE 2.1 full server applications. Access 97 is not a full server because you cannot embed or link an Access .mdb file in an OLE 2.1 container application.


A subprogram called from within an expression in which a value is computed and returned to the program that called it through its name. Functions are classified as internal to the application language when their names are keywords. You may create your own user-defined functions in VBA by adding code between FunctionFunctionName...End Function statements.


Pertaining to the program as a whole. Global variables and constants are accessible to, and global variables may be modified by, code at the form, module, and procedure level. VBA uses the reserved word Public to create or refer to global variables.

global module

A code module (container) in which all global variables and constants are declared and in which the prototypes of any external functions contained in DLLs are declared. Use of a global module in Access applications is common but not required.


A preset group of visible or imaginary vertical and horizontal lines used to assist in aligning the position of graphic objects. In Access, the intersection of the imaginary lines is shown as dots on forms and reports in Design mode. Control objects automatically align their outlines to these dots if the Snap To Grid option is enabled. In Access Datasheet view, a set of lines that establish the demarcation of columns and rows.


In reports, one or more records that are collected into a single category, usually for the purpose of totaling. Database security systems use the term group to identify a collection of database users with common permissions.

See also [permissions]


An acronym for hardware abstraction layer, a Windows NT DLL that links specific computer hardware implementations with the Windows NT kernel. Windows NT 4.0 includes HALs for 80x86, Alpha, MIPS, and PowerPC hardware platforms.


An unsigned Long integer assigned by Windows 95 and Windows NT to uniquely identify an instance (occurrence) of a module (application, hModule), task (hTask), window (hWnd), or device context (hDC) of a graphic object. Handles in 32-bit Windows applications, including applications for Windows 95 and Windows NT, are 32-bit unsigned long integers (dw or double words). Also used to identify the sizing elements of control objects in design mode.

See also [sizing handle]

header file

A file type used by C and C++ programs to assign data types and names to variables and to declare prototypes of the functions used in the application. C header files usually carry the extension .h.

hierarchical menu

A menu with multiple levels, consisting of a main menubar that leads to one or more levels of submenus from which choices of actions are made. Almost all Windows applications use hierarchical menu structures.


Any computer on a network running an Internet Protocol (IP).

See also [IP]
See also [IP address]


A DDE (dynamic data exchange) operation in which a change in the source of the DDE data (the server) is immediately reflected in the object of the destination application (the client) that has requested it.


An acronym for the High-Performance File System used by OS/2 and (optionally) Windows NT 3.x. Windows NT 4.0 doesn't support HPFS but can connect via a network to files on HPFS volumes of Windows NT 3.x PCs.


An abbreviation for Hypertext Markup Language, a variant of SGML (Standardized General Markup Language), a page-description language for creating files that can be formatted and displayed by World Wide Web browsers.


A 32×32-pixel graphic image used to identify the application in the program manager window when the application is minimized, and in other locations in the application chosen by the programmer (such as the Help About dialog). Windows 95 also uses 16×16-pixel icons to identify the application in the title bar.


A synonym for name or symbol, usually applied to variable and constant names.


In Windows, the condition or state in which Windows and the application have processed all pending messages in the queue from user- or hardware-initiated events and are waiting for the next event to occur. The idle state is entered in VBA when the interpreter reaches the End Sub statement of the outermost nesting level of procedures for a form or control object.

immediate window

Replaced in Access 95 and other VBA-enabled applications by the Debug window.

See also [Debug window]


For arrays, the position of the particular element with respect to others, usually beginning with 0 as the first element. When used with database files or tables, index refers to a lookup table, usually in the form of a file or component of a file, that relates the value of a field in the indexed file to its record or page number and location in the page (if pages are used).

infinite loop

A Do While...Loop, For...Next, or similar program flow-control structure in which the condition to exit the loop and continue with succeeding statements is never fulfilled. In For...Next loops, infinite looping occurs when the loop counter is set to a value less than that assigned to the To embedded keyword within the structure.


In programming, setting all variables to their default values and resetting the point of execution to the first executable line of code. Initialization is accomplished automatically in VBA when you start an application.

inner query

Synonym for subquery.

See also [subquery]

in-place activation

The ability to activate an object (launch another application) and have the container application take on the capabilities of the other application. The primary feature of in-place activation (also called in-situ activation) is that the other application's menu choices merge with or replace the container application's menu choices in the active window.


A term applied to (OLE) Automation servers, also called OLE DLLs, that operate within the same process space (memory allocation) of the (OLE) Automation client. In-process servers commonly are called InProc servers.

See also [out-of-process]

insertion point

The position of the cursor within a block of text. When the cursor is in a text field, it is called the caret in Windows.


The temporary existence of a loaded application or one or more of its windows.


The process of creating an instance of an object in memory.


A whole number. In most programming languages, an integer is a data type that occupies two bytes (16 bits). Integers may have signs (as in the VBA Integer data type), taking on values from −32,768 to +32,767, or be unsigned. In the latter case, integers can represent numbers up to 65,535.


A connection between two dissimilar COM objects or (OLE) Automation clients and servers. Another common phrase is user interface, meaning the "connection" between the display/keyboard combination and the user. Adapter cards constitute the interface between the PC data bus and peripheral devices such as displays, modems, CD-ROMs, and the like. Drivers act as a software interface between Windows and the adapter cards. A bridge is an interface between two dissimilar networks. (OLE) Automation uses Iole_ interfaces for interprocess communication. Use of interface as a verb is jargon.


The group of data elements included in both tables that participate in a JOIN operation.


A private network that uses Internet protocols and common Internet applications (such as Web browsers) to emulate the public Internet. Intranets on LANs and high-speed WANs provide increased privacy and improved performance compared with today's Internet.

invocation path

The route through which an object or routine is invoked. If the routine is deeply nested, the path may be quite circuitous.


To cause execution of a block of code, particularly a procedure or sub-procedure. Also indicates application of a method to an object.


An abbreviation for Internet Protocol, the basic network transmission protocol of the Internet.

IP address

The 32-bit hexadecimal address of a host, gateway, or router on an IP network. For convenience, IP addresses are specified as the decimal value of the four address bytes, separated by periods, as in Addresses are classified as types A, B, and C, depending on the subnet mask applied.

See also [subnet mask]


Abbreviation for Internetwork Packet Exchange/Sequenced Packet Exchange, the transport protocol of Novell NetWare, supported by Windows NT's NWLink service.


An acronym for Integrated Services Digital Network, a switched telephone service that provides mid-band digital communication capabilities used for Internet connections and for remote access to LANs, as well as voice communication. Windows NT 4.0 has built-in support for ISDN modems, more properly called network terminators.


The name given to each element contained in a list or the list component of a combo box.


Microsoft's name for the database engine native to Access and Visual Basic. The name Jet came from the acronym for Joint Engine Technology, the predecessor of Jet 3.5 used by Access and Visual Basic 5.0.


A basic operation, initiated by the SQL JOIN statement, that links the rows or records of two or more tables by one or more columns in each table.


In programming, execution of code in a sequence that is not the same as the sequence in which the code appears in the source code. In most cases, a jump skips over a number of lines of code, the result of evaluation of a conditional expression. In some cases, a jump causes another subroutine to be executed.

key or key field

A field that identifies a record by its value. Tables are usually indexed on key fields. For a field to be a key field, each data item in the field must possess a unique value.

See also [primary key]
See also [foreign key]

key or key field

A field that identifies a record by its value. Tables are usually indexed on key fields. For a field to be a key field, each data item in the field must possess a unique value.

See also [primary key]
See also [foreign key]

key value

A value of a key field included in an index.


A word that has specific meaning to the interpreter or compiler in use and causes predefined events to occur when encountered in source code. Keywords differ from reserved words because you can use keywords as variable, procedure, or function names. Using keywords for this purpose, however, is not a good programming practice. You cannot use a reserved word as a variable or constant name.


In VBA programming, a name given to a target line in the source code at which execution results on the prior execution of a GoTo LabelName instruction. A label also is an Access control object that displays, but cannot update, text values.


An acronym for local area network, a system comprising multiple computers that are physically interconnected through network adapter cards and cabling. LANs allow one computer to share specified resources, such as disk drives, printers, and modems, with other computers on the LAN.


To start a Windows application.

leaf level

The lowest level of an index. Indexes derive the names of their elements from the objects found on trees, such as trunks, limbs, and leaves.


A collection of functions, compiled as a group and accessible to applications by calling the function name and any required arguments. DLLs are one type of library; those used by compilers to provide built-in functions are another type.

library database

An Access database that is automatically attached to Access when you launch it. Access library databases usually have the extension .mda; encrypted libraries use the extension .mde. Attachment of library databases to Access is controlled by Registry entries.

linked object

A source document in a compound document that is included by reference to a file that contains the object's data, rather than the source document be embedded in the compound document.

linked table

A table that is not stored in the currently open Access database (native or base table), but which you can manipulate as if it were a native table. Linked tables were called attached tables in Access 1.x and 2.0.


A Windows control object that provides a list of items that the user can choose from with the mouse or the cursor keys.


A request for an exclusive lock on a data item that is repeatedly denied because of shared locks imposed by other users.


The scope of a variable declared within a procedure, rather than at the form, module, or global level. Local variables are visible (defined) only within the procedure in which they were declared. VBA uses the prefix Private to define functions, sub-procedures, and variable of local scope.

local area network

See also [LAN]


A restriction of access to a table, portion of a table, or data item imposed to maintain data integrity of a database. Locks may be shared, in which case more than one user can access the locked element(s), or exclusive, where the user with the exclusive lock prevents other users from creating simultaneous shared or exclusive locks on the ele-ment(s). Access uses page locks (2K of the .mdb file), which may lock several adjacent records. Some RDBMSs provide row locks that lock only a single record. SQL Server 6.5 uses row locking for INSERT operations and page locking for UPDATE and DELETE operations.


A synonym for Boolean, a data type that may have true or false values only. Logical is also used to define a class of operators whose result is only True or False. VBA includes a Boolean data type.


A compound program flow-control structure that causes statements contained between the instructions that designate the beginning and end of the structure to be repeatedly executed until a given condition is satisfied. When the condition is satisfied, program execution continues at the source code line after the loop termination statement.


An acronym for lightweight remote procedure call used for OLE 2+ and some ActiveX operations between OLE clients and OLE full servers on a single computer. LRPC requires that both applications involved in the procedure call be resident on the same computer.

See also [remote procedure call RPC]

machine language

Program code in the form of instructions that have meaning to and can be acted on by the computer hardware and operating system. Object files compiled from source code are in machine language, as are executable files that consist of object files linked with library files.


A set of one or more instructions, called actions by Access, that respond to events. Macros and VBA code, which can substitute for Access macros, are used to automate Access applications. Although Access 97 supports macros for backward compatibility with earlier versions, VBA is the preferred method of programming responses to events. Future version of Access may not support macros.


The first element of a number expressed in scientific notation that is multiplied by the power of 10 given in the exponent to obtain the actual number. For +1.23E3, the exponent is 3, so you multiply the mantissa, 1.23, by 1,000 (10 to the third power) to obtain the result: 1,230.


Acronym for the Windows Messaging API created by Microsoft for use with Microsoft Mail, which implements Simple MAPI. Microsoft Exchange Server implements MAPI 1.0 (also called Extended MAPI).

master database

A database that controls user access to other databases, usually in a client/server system.

master table

A table containing data on which detail data in another table is dependent. Master tables have a primary key that is matched to a foreign key in a detail table and often have a one-to-many relationship with detail tables. They sometimes are called base tables.

MDI server

An OLE 2+ server that supports multiple compound documents within a single running instance of the application.


An Access field data type that can store text with a length of up to about 64,000 bytes. (The length of the Text field data type is limited to 255 bytes.)


A set of choices from which the user determines the next set action to take. The CUA or Common User Access specification developed by IBM governs the menu design in Windows.


A type of graphics file, used by Windows and other applications, that stores the objects displayed in the form of mathematical descriptions of lines and surfaces. Windows metafiles, which use the extension .wmf, are a special form of metafiles. Windows 95 and Windows NT 4.0 also supports enhanced metafiles (.emf).


One characteristic of an object and a classification of keywords in VBA. Methods are the procedures that are applicable to an Access object. Methods that are applicable to a class of objects are inherited by other objects of the same class and may be modified to suit the requirements of the object by a characteristic of an object.


An applet with OLE server capabilities that you cannot run as a stand-alone application.


See also [disk mirroring]


An abbreviation for Microsoft Internet Security Framework, a set of high-level security services that rely on CryptoAPI 2.0 functions to provide certificate- and password-based authentication. MISF also incorporates secure channel communication by using SSL (Secure Sockets Layer) 2.0 and 3.0, plus PCT (Personal Communications Technology), SET (Secure Electronic Transactions) for credit-card purchases, and the Microsoft Certificate Server for issuing authentication certificates.


A cliché used in software and hardware advertising to describe the need to use the promoted product if you want to create a reliable database system.


A dialog that must be closed before users can take further action within the application.


A window or dialog that users can close or minimize without taking any other action; the opposite of modal.


A block of code, consisting of one or more procedures, for which the source code is stored in a single location (a Form or Module object in Access). In a compiled language, a code module is compiled to a single object file.

module level

Variables and constants that are declared in the Declarations section of a module. These variables have module-level scope and are visible (defined) to all procedures contained within the module, unless declared Public, in which case the variables are visible to all procedures.


A handle to the source of a compound document object.


A name often used in place of the more proper terms, display or video display unit (VDU).


The combination of sound and graphic images within a single application for the purpose of selling new computer hardware and software. Related outcomes are the creation of animated presentations that incorporate sound effects and graphics, as well as expansion of the market for PCs in the music industry.


The ability of a computer with two or more CPUs to allocate tasks (threads) to a specific CPU. Symmetrical multiprocessing (SMP), implemented in Windows NT, distributes tasks among CPUs by means of a load-sharing methodology. Applications must be multithreaded to take advantage of SMP.


The ability of a computer with a single CPU to simulate the processing of more than one task at a time. Multitasking is effective when one or more of the applications spends most of its time in an idle state waiting for a user-initiated event, such as a keystroke or mouse click.


An application that contains more than one thread of execution; a task or set of tasks that executes semi-independently of other task(s). The Jet 3.0 database engine is multithreaded (three threads); Access 95 and VBA are each single-threaded.

See also [thread]


Concurrent use of a single computer by more than one user, usually through the use of remote terminals. UNIX is inherently a multiuser operating system. Access uses the term multiuser to refer to Access applications that share a common .mdb file on a network file server.

named pipes

A method of interprocess communication, originally developed for OS/2, that provides a secure channel for network communication.

natural join

A SQL JOIN operation in which the values of the columns engaged in the join are compared, with all columns of each table in the join that do not duplicate other columns being included in the result. Same as an equi-join except that the joined columns are not duplicated in the result.

See also [equi-join]


An abbreviation for NetBEUI Frame, the transport packet structure used by NetBEUI.


An expression applied to procedures that call other procedures within an application. The called procedures are said to be nested within the calling procedure. When many calls to subprocedures and sub-subprocedures are made, the last one in the sequence is said to be deeply nested.

nested object

An OLE 2+ compound document incorporated in another OLE 2+ compound document. You can nest OLE 2+ documents as deeply as you like. OLE 1.0 does not supported nested objects.

nested query

A SQL SELECT statement that contains subqueries.

See also [subquery]


An abbreviation for NetBIOS Extended User Interface, the transport protocol of Microsoft Networking. NetBEUI isn't a routable network, so its popularity is declining compared with TCP/IP.


An abbreviation for Network Basic Input/Output System, the original network API for MS-DOS and the foundation for NetBEUI.

newline pair

A combination of a carriage return, the Enter key (CR or Chr$(13)), and line feed (LF or Chr$(10)) used to terminate a line of text on-screen or within a text file. Other characters or combinations may be substituted for the CR/LF pair to indicate the type of newline character (soft, hard, deletable, and so on). The VBA newline constant is VbCrLf.


An acronym for Network File Server, a file format and set of drivers, created by Sun Microsystems, that allows DOS/Windows and UNIX applications to share a single server disk drive running under UNIX.

non-clustered index

An index that stores key values and pointers to data based on these values. In this case, the leaf level points to data pages rather than to the data itself, as is the case for a clustered index. Equivalent to SET INDEX TO field_name in xBase.

normal forms

A set of five rules, the first three originally defined by Dr. E.F. Cobb, that are used to design relational databases. Five normal forms are generally accepted in the creation of relational databases.

See also [first normal form]
See also [second normal form]
See also [third normal form]
See also [fourth normal form]
See also [fifth normal form]


Creation of a database according to the five generally accepted rules of normal forms.

See also [normal forms]

not-equal join

A JOIN statement that specifies that the columns engaged in the join do not equal one another. In Access, you must specify a not-equal join by using the SQL WHERE field1 <> field2 clause.


An acronym for New Technology used by Windows NT.


An acronym for New Technology File System, Windows NT's replacement for the DOS FAT (file allocation table) and OS/2's HPFS (high-performance file system). NTFS offers many advantages over other file systems, including improved security and the ability to reconstruct files in the event of hardware failures. Windows 3.1+ and Windows 95 can access files stored on NTFS volumes via a network connection but cannot open NTFS files directly.


A variable of no value or of unknown value. The default values—0 for numeric variables and an empty string ("") for string variables—are not the same as the Null value. The NULL value in SQL statements specifies a data cell with no value assigned to the cell.


In programming, elements that combine data (properties) and behavior (methods) in a single container of code called an object. An Access Form or Report object is a member of the class of Access Database objects; a particular control object is a subclass of the control objects class. Objects inherit their properties and methods from the classes above them in the hierarchy and can modify the properties and methods to suit their own purposes. The code container may be part of the language itself, or you may define your own objects in source code.

object code

Code in machine-readable form that your computer's CPU and operating system can execute. Object code is usually linked with libraries to create an executable file.

object frame

An Access control object that contains and displays or plays an OLE object. Bound object frames display or play OLE objects contained in OLE Object fields of Access tables. Unbound object frames display or play objects that are embedded in a Form or Report object or are linked to a file that supplies the object's data. ActiveX Controls (formerly OLE Controls) are inserted into bound or unbound object frames, depending on whether the ActiveX Control is classified as a data-bound control.

object library

A file with the extension .olb that contains information on the objects, properties, and methods exposed by an .exe or .dll file of the same file name that supports OLE Automation.

object permissions

Permissions granted by the database administrator for others to view and modify the values of database objects, including data in tables.


An acronym for the Microsoft Open Database Connectivity API, a set of functions that provides access to client/server RDBMSs, desktop database files, text files, and Excel worksheet files through ODBC drivers. Access 95 uses 32-bit ODBC 3.0 and requires 32-bit ODBC drivers. ODBC most commonly is used to connect to client/server databases, such as Microsoft SQL Server, Sybase System 10+, Informix, and Oracle 7. Access 95 includes a 32-bit ODBC driver for Microsoft SQL Server 4.2+.


A new feature of the Jet 3.5 database engine that lets you use ODBC to access client/server databases without needing to load all of Jet 3.5. ODBCDirect conserves client resources if you need to connect only to SQL Server or another client/server RDBMS. You create an ODBCDirect workspace by using the dbUseODBC constant as the value of the Type argument of the CreateWorkspace method. ODBCDirect is closely related to the Remote Data Object (RDO).

See also [Remote Data Object (RDO)]


An acronym for Office 97 Developer Edition, the replacement for the Access 2.0 and 95 Access Developer's Toolkit (ADT). The ODE includes a royalty-free license to distribute Msaccess.exe for runtime use, the runtime interpreter for VBA 5.0 (Vbrun500.dll), the runtime version of Microsoft Graph 8.0 (Graph8.exe and Graph8rt.srg), additional ActiveX controls, and other distributable components of Access 97. The ODE also includes the Setup Wizard, which you use to create images of the distribution disks for your application. Other developer-oriented features of the ODE are three printed manuals, the Replication Manager, and the Microsoft Help Compiler.


The number of bytes from a reference point, usually the beginning of a file, to the particular byte of interest. The first byte in a file, when offset is used to specify location, is always 0.

OLE Automation

An extension of OLE 2+ that provides the framework (interfaces) for applications and libraries to expose programmable objects that can be manipulated by client applications. Applications that expose programmable objects are called (OLE) Automation servers.

See also [automation]
See also [programmable object]

OLE Control

An in-process OLE Automation server with the extension .ocx that exposes a single object, plus the properties, methods, and events of the object. Exposing events differentiates OLE Controls from other types of (OLE) Automation servers. Access 95 referred to OLE Controls (the first Microsoft term) as Custom Controls; the term Custom Control is more commonly used for 16-bit Visual Basic Extensions (VBXs). OLE Controls have been superseded by 32-bit ActiveX controls.

See also [ActiveX controls]


A new Microsoft framework for providing a uniform interface to data from a variety of sources, including text files and mainframe databases. OLE DB doesn't replace ODBC, but includes an ODBC provider that takes the place of the ODBC driver manager.

See also [ActiveX data objects]
See also [ODBC]


A synonym for an in-process OLE Automation server implemented as a Windows DLL.

See also [in-process]


A standard proposed by Apple Computer, Borland International, Lotus Development, Novell, and other competitors of Microsoft to supplant or replace OLE 2+.


One variable or constant on which an operator acts. In 1 + 2 = 3, 1 and 2 are operands, + and = are the operators.

See also [operator]

operating system

Applications that translate basic instructions, such as keyboard input, to language understood by the computer. The most common operating systems used with personal computers are MS-DOS (Microsoft Disk Operating System), Windows 95, Windows NT, UNIX, and OS/2.


A keyword or reserved symbol that, in its unary form, acts on a single variable, or otherwise acts on two variables, to give a result. Operators may be of the conventional mathematics type such as + (add), − (subtract), / (divide), and * (multiply), as well as logical, such as And or Not. The unary minus (−), when applied to a single variable in a statement such as intVar = −intVar, inverts the sign of intVar from - to + or from + to -.

optimistic locking

A method of locking a record or page of a table that makes the assumption that the probability of other users locking the same record or page is low. With optimistic locking, the record or page is locked only when the data is updated, not during the editing process (LockEdits property set to False).

option button

A synonym for radio button, the original terminology in the CUA specification. Option buttons are circular control objects whose center is filled when selected. Only one option button of a group can be selected; if an option button is placed directly on a form, the form becomes the group and only one option button can be selected.

outer join

A SQL JOIN operation in which all rows of the joined tables are returned, whether or not a match is made between columns. SQL database managers that do not support the OUTER JOIN reserved words use the *= (LEFT JOIN) operator to specify that all the rows in the preceding table return, and =* (RIGHT JOIN) to return all the rows in the succeeding table.

outer query

A synonym for the primary query in a statement that includes a subquery.

See also [subquery]


An (OLE) Automation server in the form of an executable (.exe) file that operates in its own process space (memory allocation) and uses LRPCs (lightweight remote procedure calls) to communicate with the Automation client. The term OutOfProc often is used as shorthand for out-of-process.


In tables of client/server RDBMSs, such as Microsoft SQL Server and Access databases, a 2K block that contains records of tables. Client/server and Access databases lock pages, while DOS desktop databases usually lock individual records. Page-locking is required by most RDBMSs when variable-length records are used in tables.


The equivalent of an argument, but associated with the procedure that receives the value of an argument from the calling function. The terms parameter and argument, however, are often used interchangeably.


The process of determining if a particular expression is contained within another expression. Parsing breaks program statements into keywords, operators, operands, arguments, and parameters for subsequent processing of each by the computer. Parsing string variables involves searching for the occurrence of a particular character or set of characters in the string, and then taking a specified set of actions when found or not found.


An acronym for Primary Domain Controller, the Windows NT server in a domain that's responsible for maintaining user and group accounts for a domain. Primary and Backup Domain Controllers authenticate domain users during the logon process.

See also [BDC]


Authority given by the system administrator, database administrator, or database owner to perform operations on a network or on data objects in a database.

persistent (graphics)

A Windows graphic image that survives movement, resizing, or overwriting of the window in which it appears. Persistent images are stored in global memory blocks and are not released until the window containing them is destroyed.

persistent (objects)

An object that is stored in the form of a file or an element of a file, rather than only in memory. Table and QueryDef objects are persistent because they're stored in .mdb files. Recordset objects, on the other hand, are stored in memory. Such objects are called temporal or impersistent objects.

pessimistic locking

A method of locking a record or page of a table that makes the assumption that the probability of other users locking the same record or page is high. With pessimistic locking, the record or page is locked during the editing and updating process (LockEdits property set to True).


In typography, the unit of measurement of the vertical dimension of a font, about 1/72 of an inch. The point is also a unit of measurement in Windows, where it represents exactly 1/72 of a logical inch, or 20 twips. Unless otherwise specified, all distance measurements in VBA are in twips.


A data type that comprises a number representing a memory location. Near pointers are constrained to the 64K default local data segment. Far pointers can access any location in the computer's memory. Pointers are used extensively in C-language applications to access elements of arrays, strings, structures, and the like. VBA has only one pointer data type—to a zero-terminated string when the ByVal...As String keywords are applied to a VBA string passed to an external function contained in a dynamic link library.


In DDE terminology, the transmission of an unrequested data item to a DDE server by the DDE client. In BASIC language terminology, placing a byte of data in a specific memory location. VBA does not support the BASIC POKE keyword and uses the DDEPoke method for DDE operations.


An acronym for Point-to-Point Protocol, the most common Internet protocol for connection to TCP/IP networks via conventional and ISDN modems.


An acronym for Point-to-Point Tunneling Protocol, a Microsoft-sponsored protocol included with Windows NT 4.0 that uses encryption to assure privacy of communication over the Internet.

See also [VPN]


The sequence of execution of operators in statements that contain more than one operator.

primary key

The column or columns whose individual or combined values (in the case of a composite primary key) uniquely identify a row in a table.

primary verb

The default verb for activating an OLE 2+ object. Edit is the default verb for most OLE objects, except multimedia objects, whose default verb is usually Play.

print zone

The area of a sheet of paper on which a printer can create an image. For most laser printers and standard dot-matrix printers, this area is 8 inches wide. The vertical dimension is unlimited for dot-matrix printers and usually is 13.5 inches for a laser printer with legal-size paper capabilities.

printer object

A VBA object representing the printer chosen as the default by the Control Panel Printers tool's Set Default choice.


A self-contained collection of source code statements, executable as an entity. All VBA procedures begin with the reserved word Sub or Function (which may be preceded by the Public, Private, or Static reserved words) and terminate with End Sub or End Function.

process server

An unofficial term used in this book to specify an (OLE) Automation server, either in-process or out-of-process, that does not provide user-interface components, such as dialogs or windows. Process servers often are used in three-tier client/server applications to implement business rules.

See also [business rules]
See also [three-tier]


All code required to create an application, consisting basically of declar-ations, statements, and—in Windows—resource definition and help files.

programmable object

An object exposed by an (OLE) Automation server with a set of properties and methods applicable to the object. The application programming language of an (OLE) Automation client application can manipulate the exposed object.


Identifies the desired subset of the columns contained in a table. You create a projection with a query that defines the fields of the table you want to display but without criteria that limit the records that are displayed.

Properties window

A window that displays the names and properties of Access Table, Form, Report, and Control objects.


One of two principal characteristics of objects (the other is methods). Properties define the manifestation of the object—for example, its appearance. Properties may be defined for an object or for the class of objects to which the particular object belongs, in which case they are said to be inherited.


A description of the method by which networked computers communicate. Windows NT and Windows 95 allow the simultaneous use of multiple network protocols, including TCP/IP, NetBEUI, and IPX/SPX.

protocol stack

Network protocol software that implements a specific protocol, such as TCP/IP.


An object contained within other OLE 2+ objects, such as the cells of a spreadsheet object.


A search condition that data values must meet to be included in the result of the search.


To precede the name of a database object with the name of the database and the object's owner, or to precede the name of a file with its drive designator and the path to the directory in which the file is stored. The terms well-qualified path and well-formed path to a file appear often in documentation.


A request to retrieve data from a database with the SQL SELECT instruction or to manipulate data in the database, called an action query by Access.


A persistent Access object that stores the Access SQL statements that define a query. QueryDef objects are optimized, when applicable, by the Jet database engine's query optimizer and stored in a special optimized format.


An acronym for redundant array of inexpensive disks, a method of connecting multiple disk drives to a single controller card to achieve faster data throughput, data storage redundancy for fault tolerance, or both.

See also [disk mirroring]
See also [disk striping]
See also [fault tolerance]


An abbreviation for relational database management system, an application that can create, organize, and edit databases; display data through user-selected views; and print formatted reports. Most RDBMSs include at least a macro or macro language, and most provide a system programming language. dBASE, Paradox, and FoxPro are desktop RDBMSs.


A synonym for a user-defined data type, called a structure in C and C++. Also used in database applications to define a single element of a relational database file that contains each field defined for the file. Records don't need to contain data to exist, but Jet does not append a record without a value in at least one field. A record is the logical equivalent of the row of a table.


A temporary local image of a table or a query result set stored in the PC's memory or virtual memory. DAO or ODBCDirect Recordset objects underlie Access's data-bound forms, reports, and controls. Recordset objects are the primary means for manipulating data with VBA.


Software that intercepts requests for remotely provided services, such as files in server shares, and sends the request to the appropriate computer on the network.


In VBA, the incorporation of pointers to specific sets of programmable objects exposed by Automation servers and manipulated by VBA code in the Automation client. You create a VBA reference to a set of objects exposed by an Automation server, such as Microsoft Excel 97, in the References dialog that is accessible by choosing Tools, Re ferences when a module is the active Access object. After you declare a reference to the set of objects, the VBA pseudo-compiler checks the syntax of your code against the syntax specified for the referenced object. You also can use predefined intrinsic constants for the referenced objects in your VBA code.

referential integrity

Rules governing the relationships between primary keys and foreign keys of tables within a relational database that determine data consistency. Referential integrity requires that the values of every foreign key in every table be matched by the value of a primary key in another table. Access 2+ includes features for maintaining referential integrity, such as cascading updates and cascading deletions.


To redisplay records in Access's datasheet views or in a form or report so as to reflect changes others in a multiuser environment have made to the records.


A database that contains information required for the operation of Windows 95 and Windows NT, plus applications installed under Windows 95 and Windows NT. The Windows Registry takes the place of Windows 3.1+'s REG.DAT, WIN.INI, and SYSTEM.INI files, plus PROFILE.INI files installed by Windows 3.1 applications. The Registry also includes user information, such as user IDs, encrypted passwords, and permissions. Windows 95 and Windows NT include Regedit.exe for editing the Registry. ActiveX Components and OLE 2+ servers add entries to the Registry to specify the location of their exe files. Automation servers add Registry entries for each object they expose. The Windows NT and Windows 95 Registries differ in structure and thus are incompatible.


Synonym for a table or a data table in an RDBMS.

relational database

See also [RDBMS]

relational operators

Operators such as >, <, <>, and = that compare the values of two operands and return True or False depending on the values compared. They are sometimes called comparative operators.

Remote Automation Object

An out-of-process (OLE) Automation server, usually called an RAO, that resides on a server and is accessible to RAO-compliant applications that connect to the server with DCOM.

See also [DCOM]

Remote Data Object RDO

A substitute for the Jet 3.5 Data Access Object that provides a more direct connection to the ODBC API. Access 97 offers ODBCDirect as an alternative to RDO. You can reference the RDO 2.0 type library in Access 97 applications and write VBA code for the RDO to speed queries against client/server databases. Like ODBCDirect, RDO also offers additional RDBMS connection management features.

See also [ODBCDirect]

remote procedure call RPC

An interprocess communication method that allows an application to run specific parts of the application on more than one computer in a distributed computing environment. Visual Basic 5.0 can create Remote Automation Objects (RAOs) that use RPCs for communication over a network.


The process of duplicating database objects (usually tables) in more than one location, including a method of periodically rationalizing (synchronizing) updates to the objects. Unlike Access 95, Access 97 supports partial replication. Database replication is an alternative to the two-phase commit process. Microsoft SQL Server 6.5 supports replication of databases across multiple Windows NT servers. Access 97 includes a mini-replication feature designed for mobile users of Access databases running Windows 95.

See also [Briefcase replication]
See also [two-phase commit]

reserved word

A word that comprises the vocabulary of a programming language and that is reserved for specific use by the programming language. You cannot assign a reserved word as the name of a constant, variable, function, or subprocedure. Although the terms reserved word and keyword often are used interchangeably, they do not describe an identical set of words. VBA reserved words are shown in bold monospace type throughout this book.

See also [keyword]


A query statement that defines a subset of the rows of a table based on the value of one or more of its columns.


A method of specifying colors by using numbers to specify the individual intensities of its red, green, and blue components, the colors created by the three "guns" of the cathode-ray tube (CRT) of a color display.


An acronym for the Windows Resource Interchange File Format used with the Multimedia Extensions to Windows. Depending on their definition, these files may contain MIDI sequence, sample dump or system exclusive data, waveform files, or data to create graphic images. RIFF is the preferred file format, at least by Microsoft, for multimedia files.


In transaction processing, the cancellation of a proposed transaction that modifies one or more tables and undoes changes, if any, made by the transaction prior to a COMMIT or COMMIT TRANSACTION SQL statement.


A synonym for procedure.


A set of related columns that describes a specific data entity. A synonym for record.

row aggregation functions

See also [aggregate functions]


A specification that determines the data type and data value that may be entered in a column of a table. Rules are classified as validation rules and business rules.

See also [business rules]

run mode

The mode of Access operation when Access is executing your database application. Run mode is called runtime by Microsoft; however, the term runtime normally is used with errors that occur when running the executable version of an application.

running state

The state of an OLE 2+ object in which the application that created the object is launched and has control of the object.


An acronym for Security Accounts Manager, a Windows NT subsystem that maintains a database of user account names and passwords for authentication.


The property of a multiprocessing computer that defines the extent to which addition of more processors increases aggregate computing capability. Windows NT 4.0 Server is generally considered to be scalable to eight Intel processors.


In programming, the extent of visibility (definition) of a variable. VBA has global (Public, visible to all objects and procedures in the application), form/report (visible to all objects and procedures within a single form or report), module (visible to all procedures in a single module file), and local (Private, visible only within the procedure in which declared) scope. The scope of a variable depends on where it is declared.

See also [form-level]
See also [global]
See also [local]
See also [module level]

screen object

An Access VBA object and object class defined as the entire usable area of the video display unit. All visible form and control objects are members of subclasses of the Screen object.

scroll bar

Vertical and horizontal bars at the right side and bottom, respectively, of a multiline text box that allow the user to scroll the window to expose otherwise hidden text. Access also provides scroll bars for tables and queries in run mode (Datasheet view) and for forms or reports that exceed the limits of the display.

SDI server

An OLE 2+ server that supports only a single compound document (Single Document Interface) within an instance of the application. SDI is the preferred design of applications for Windows 95; however, all Microsoft Office 95 productivity applications are multiple-document interface (MDI) applications. Windows 95's Explorer and Exchange client are examples of SDI applications.

second normal form

The rule for relational databases requiring that columns that are not key fields each be related to the key field—that is, a row may not contain values in data cells that do not pertain to the value of the key field. In an invoice item table, for instance, the columns of each row must pertain solely to the value of the invoice number key field.


To locate a specific byte, record, or chunk within a disk file. The Seek method of Access VBA can be used only with Recordset objects of the Table type and requires that the table be indexed.

select list

The list of column names, separated by commas, that specify the columns to be included in the result of a SELECT statement.


In Windows, one or more objects that have been chosen by clicking the object or otherwise assigning the focus to the object. When used with text, it means the highlighted text that appears in a text box or window.

See also [restriction]


A SQL JOIN operation used to compare values within the columns of one table. Self-joins join a table with itself, requiring that the table be assigned two different names, one of which must be an alias.


A reserved symbol used to distinguish one item from another, as exemplified by the use of the exclamation point (!, bang character) in Access to separate the name of an object class from a specific object of the class, and an object contained within a specified object. The period separator (., dot) separates the names of objects and their methods or properties.

sequential access file

A file in which one record follows another in the sequence applicable to the application. Text files, for the most part, are sequential.


A computer on a LAN that provides services or resources to client computers by sharing its resources. Servers may be dedicated, in which case they share their resources but do not use them themselves except in performing administrative tasks. Servers in client/server databases are ordinarily dedicated to making database resources available to client computers. Servers may also be used to run applications for users, in which case the server is called an application server. Peer-to-peer or workgroup servers, such as those created by using Windows 95 and Windows NT to share disk folders, are another class of server.


In Access 97, an instance of the Jet 3.5 database engine for a single user represented by the Workspace object. You can establish multiple sessions that become members of the Workspaces collection. In RDBMS terminology, the period between the time that a user opens a connection to a database and the time that the connection to the database is closed.

shared application memory

Memory that is allocated between processes involved in an LRPC call.

See also [LRPC]

shared lock

A lock created by read-only operations that does not enable the user who creates the shared lock to modify the data. Other users can place shared locks on data so they can read it, but none can apply an exclusive lock on the data while any shared locks are in effect.

shortcut key

A Ctrl+key combination that provides access to a menu choice, macro, or other function of the application in lieu of selection with the mouse.

See also [accelerator key]


An acronym for security ID, a numeric value that identifies a logged-on user who has been authenticated by Windows NT or a user group.


A debugging process by which the source code is executed one line at a time to allow you to inspect the value of variables, find infinite loops, or remove other types of bugs.

sizing handle

The small black rectangles on the perimeter of Access control objects that appear on the surface of the form or report in design mode when the object is selected. You drag the handles of the rectangles to shrink or enlarge the size of control objects.


An acronym for Server Message Block, a networking protocol used by NetBEUI to implement Microsoft Networking.

source code

The readable form of code that you create in a high-level language. Source code is converted to machine-language object code by a compiler or interpreter.

source document

A term used by OLE 1.0 to refer to a compound object in a container document.


An acronym, pronounced as sequel or seekel, for Structured Query Language, a language developed by IBM Corporation for processing data contained in mainframe computer databases. (Sequel is the name of a language, similar to SQL, developed by IBM but no longer in use.) SQL has now been institutionalized by the creation of an ANSI standard for the language.

SQL aggregate functions

See also [aggregate functions]


A syntactically acceptable (to the interpreter or compiler of the chosen language) combination of instructions or keywords and symbols, constants, and variables that must appear on a single line or use the line-continuation pair (a space followed by an underscore) to use multiple lines.


When referring to a variable, a variable that retains its last value until another is assigned, even though the procedure in which it is defined has completed execution. All global variables are static. Variables declared as Static are similar to global variables, but their visibility is limited to their declared scope. The term is also used to distinguish statically linked (conventional) executable files from those that use DLLs.

stored procedure

A set of SQL statements (and with those RDBMSs that support them, flow-control statements) that are stored under a procedure name so that the statements can be executed as a group by the database server. Some RDBMSs, such as Micro-soft and Sybase SQL Server, precompile stored procedures so that they execute more rapidly.


A data type used to contain textual material, such as alphabetic characters and punctuation symbols. Numbers may be included in or constitute the value of string variables but cannot be manipulated by mathematical operators.

stripe set

See also [disk striping]
See also [fault tolerance]


Two or more keywords used together to create an instruction, which is usually conditional in nature. In C and C++ programming, a user-defined data type.

See also [compound]

Structured Query Language

See also [SQL]


A procedure or user-defined function that, in VBA, consists only of SubSubName...End Sub or FunctionFnName...End Function lines with no intervening code. Access automatically creates stubs for subprocedures for event-handling code stored in Form and Report objects. Stubs block out the procedures required by the application that can be called by the main program. The intervening code statements are filled in during the programming process.


In typography, a characteristic or set of attributes of a member of a family of typefaces created by an outline or bitmap designed specifically to implement it. Styles include bold, italic, bold italic, bold italic condensed, and so forth. Styles may contain attributes for weight (bold, demi-bold, black), form (italic, roman), and spacing (condensed or expanded) in various combinations.


A form contained within another form.


A set of choices presented when a main menu choice is made. In Windows, the first-level submenus are similar to drop-down dialogs. Second-level submenus usually appear horizontally at the point of the first submenu choice.

subnet mask

A local bit mask (set of flags) that specifies which bits of the IP address specify a particular IP network or a host within a subnetwork. An IP address of with a subnet mask of specifies host 1 on subnet The subnet mask determines the maximum number of hosts on a subnetwork.


A procedure called by another procedure other than the main procedure (WinMain in Windows). In Access, all procedures except functions are sub-procedures because Msaccess.exe contains the WinMain function.


A SQL SELECT statement that is included (nested) within another SELECT, INSERT, UPDATE, or DELETE statement, or nested within another subquery.


A report contained within another report.


The rules governing the expression of a language. As with English, Spanish, Esperanto, or Swahili, programming languages each have their own syntax. Some languages allow much more latitude (irregular forms) in their syntax. VBA has a relatively rigid syntax, while C provides more flexibility at the expense of complexity.

system administrator

The individual(s) responsible for the administrative functions for all applications on a LAN or users of a UNIX cluster or network, usually including supervision of all databases on servers attached to the LAN. If the system administrator's (SA's) responsibility is limited to databases, the term database administrator (DBA) is ordinarily assigned.

system colors

The 20 standard colors used by Windows for elements of its predefined objects such as backgrounds, scroll bars, borders, and title bars. You may change the system colors from the defaults through Control Panel's Color and Desktop tools.

system databases

Databases that control access to databases on a server or across a LAN. Microsoft SQL Server has three system databases: the master database, which controls user databases; tempdb, which holds temporary tables; and model, which is used as the skeleton to create new user databases. Any database that is not a user database is a system database.

system function

Functions that return data about the database rather than from the content of the database.

system object

An object defined by Access rather than by the user. Examples of system objects are the Screen and Debug objects.

system table

A data dictionary table that maintains information on users of the database manager and each database under the control by the system. Access system tables carry the prefix MSys.


The most common moderate-speed telecommunication connection between LANs to create a WAN. Dedicated T-1 lines provide 1.544 Mbps of bandwidth. T-1 lines also are the most common method of connecting servers to the Internet.

tab order

The order in which the focus is assigned to multiple control objects within a form or dialog with successive pressing of the Tab key.


A database object consisting of a group of rows (records) divided into columns (fields) that contain data or Null values. A table is treated as a database device or object.


Acronym for Transport Control Protocol/Internet Protocol, the networking protocol of the Internet, UNIX networks, and the preferred protocol for Windows NT networks. TCP/IP is a routable network that supports subnetworks.

See also [IP]


An acronym for Transport Driver Interface, used by Windows NT to implement multiple network protocols by using various network interface cards.

text box

A Windows object designed to receive printable characters typed from the keyboard. Access provides two basic types: single-line and multiline. Entries in single-line text boxes are terminated with an Enter keystroke. Multiline text boxes accept more than one line of text, either by a self-contained word-wrap feature (if a horizontal scroll bar is not present) or by a Ctrl+Enter key combination.

text file

A disk file containing characters with values ordinarily ranging from Chr$(1) through Chr$(127) in which lines of text are separated from one another with newline pairs (Chr$(13) & Chr$(10)).

theta join

A SQL JOIN operation that uses comparison or relational operators in the JOIN statement.

See also [operator]

third normal form

The rule for relational databases that imposes the requirement that a column that is not a key column can't depend on another column that is not a key column. The third normal form is generally considered the most important because it is the first in the series that is not intuitive.


A part of a process, such as an executing application, that can run as an object or an entity.


The architecture of a database application, usually involving a client/server RDBMS, where the front-end application is separated from the back-end RDBMS by a middle-tier application. In Access and Visual Basic applications, the middle tier usually is implemented as an OLE Automation process server, which implements the database connection, enforces business rules, and handles transfer of data to and from databases of the RDBMS.

See also [business rules]
See also [process server]

time stamp

The date and time data attributes applied to a disk file when created or edited. SQL Server and the ODBC API support the timestamp field, which resolves concurrency issues when updating tables.


An Access control object that is invisible in run mode and used to trigger a Timer event at preselected intervals.

title bar

The heading area of a window, usually blue, in which the title of the window appears, usually in bright white (reverse).


A property of an object, such as a check box, that alternates its state when repeatedly clicked or activated by a shortcut key combination.


A group of command button icons, usually arranged horizontally across the top of a window, that perform functions that would ordinarily require one or more menu choices. Floating toolbars can be located anywhere on your display.


A collection of command buttons designated as tools, usually with icons substituted for the default appearance of a command button, that choose a method applicable to an object (usually graphic) until another tool is selected. An example is the Access Toolbox.


In DDE conversations, the name of the file or other identifying title of a collection of data. When used with help files, the name of the subject matter of a single help screen display.


A superset of ANSI SQL used by Microsoft and Sybase SQL Server. TRANSACT-SQL includes flow-control instructions and the capability to define and use stored procedures that include conditional execution and looping.


A group of processing steps that are treated as a single activity to perform a desired result. A transaction might entail all the steps necessary to modify the values in or add records to each table involved when a new invoice is created. RDBMSs that can process transactions usually include the capability to cancel the transaction by a rollback instruction or to cause it to become a permanent part of the tables with the COMMIT or COMMIT TRANSACTION statement.

See also [rollback]


A stored procedure that occurs when a user executes an instruction that may affect the referential integrity of a database. Triggers usually occur prior to the execution of INSERT, DELETE, or UPDATE statements so that the effect of the statement on referential integrity can be examined by a stored procedure prior to execution.

See also [stored procedure]


In Windows NT domain terminology, a relationship between domain controllers in which users who are members of the trusted domain can access services on another trusting domain without the need to log onto the trusting domain.


The smallest unit of measurement in Windows and the default unit of measurement of VBA. The twip is 1/20 of a point, or 1/1440 of a logical inch.

two-phase commit

A process applicable to updates to multiple (distributed) databases that prevents a transaction from completing until all the distributed databases acknowledge that the transaction can be completed. The replication process has supplanted two-phase commit in most of today's distributed client/server RDBMSs.

See also [replication]


See also [data type]

type library

A file with the extension .tlb that provides information about the types of objects exposed by an ActiveX component or (OLE) Automation server. The type library for Msaccess.exe is Msaccess.tlb.

See also [object library]


Synonym for face. A set of fonts of a single family in any available size possessing an identical style or set of attributes.


See also [operator]


An acronym for Uniform Naming Convention, the method of identifying the location of files on a remote server. UNC names begin with \\. Windows 95 and Windows NT support UNC; 32-bit Windows applications must support UNC to qualify for application of Microsoft's "Designed for Windows 95" logo. All Microsoft Office 95 applications support UNC.


A replacement for the 7- or 8-bit ASCII and ANSI representations of characters with a 16-bit model that allows a wider variety of characters to be used. Windows 95 and Windows NT support Unicode. Access 95 automatically converts Unicode to ANSI and vice-versa.

uniform data transfer UDT

The interprocess communication method used by OLE 2+. OLE 1.0 uses DDE for interprocess communication.

unique index

An index in which no two key fields or combinations of key fields on which the index is created may have the same value.


Registered trademark of Novell Incorporated (formerly of AT&T) for its multi-user operating system, now administered by the Open Systems Foundation (OSF). Extensions and modifications of UNIX include DEC Ultrix, SCO UNIX, IBM AIX, and similar products.


A permanent change to data values in one or more data tables. An update occurs when the INSERT, DELETE, UPDATE, or TRUNCATE TABLE SQL commands are executed.


A data type, also called a record, that is specified in your VBA source code by a Type...End Type declaration statement in the Declarations section of a module. The elements of the user-defined record type can be any data type valid for the language and may include other user-defined types.

user-defined transaction

A group of instructions combined under a single name and executed as a block when the name is invoked in a statement executed by the user.


The process of determining if an update to a value in a table's data cell is within a preestablished range or is a member of a set of allowable values. Validation rules establish the range or set of allowable values. Access 2+ supports validation rules at the field and table levels.


The name given to a symbol that represents or substitutes for a number (numeric), letter, or combination of letters (string).


An acronym for Visual Basic for Applications, the official name of which is "Visual Basic, Applications Edition." VBA is Microsoft's common application programming (macro) language for Access 97, Excel 5+, Project 4+, Word 8, and Visual Basic 4+. Each application has its own "flavor" of VBA as a result of automatically created references to the application's object hierarchy in VBA code. Thus, this book uses the terms Excel VBA and Project VBA when referring to a particular flavor of VBA. VBA alone is used when the subject matter is applicable to all current flavors of VBA.


The method by which the data is presented for review by the user, usually on-screen. Views can be created from subsets of columns from one or more tables by implementing the SQL CREATE VIEW instruction.

Visual Basic for Applications

See also [VBA]


Abbreviation for virtual memory, a method of mapping a combination of RAM and images of RAM stored in a paging file to provide an address space larger than that available from the RAM installed in the computer.

VM manager

The Windows NT executive service that loads memory images stored in a paging file on demand, as well as saving memory images in the paging file when no longer needed by a thread.


An abbreviation for Virtual Private Network, a means of establishing secure communication channels on the Internet with various forms of encryption.

See also [PPTP]


An acronym for wide area network, a system for connecting multiple computers in different geographical locations through the use of the switched telephone network or leased data lines, by optical or other long-distance cabling, or by infrared, radio, or satellite links.

WAVE file

A file containing waveform audio data, usually with a .wav extension.

Waveform audio

A data type standard of the Windows Multimedia Extensions that defines how digitally sampled sounds are stored in files and processed by Windows API functions calls.


An acronym for Windows Driver Model, a 32-bit architecture for creating device drivers that run under Windows NT and Windows 95.

wild card

A character that substitutes for and allows a match by any character or set of characters in its place. The DOS ? and * wild cards are similarly used in Windows applications.


An API for creating 32-bit applications that run under Windows 95 and Windows NT. Applications written to the Win32 API are purported to provide substantially improved performance when run under Windows 95 and Windows NT.


A subset of the Win32 API designed to add limited 32-bit capabilities to Windows 3.1+. Very few applications have been written to the Win32s API, which appears to have become obsolete.


A contraction used to describe the Windows help engine of Windows 95 and the files used in the creation of Windows 95 help systems. WinHelp 32 offers many useful built-in features not available in 16-bit WinHelp, including full-text indexing and search capability.


An abbreviation for Windows Sockets, a networking API for implementing Windows applications that use TCP/IP, such as FTP and Telnet.


A client computer on a LAN or WAN that is used to run applications and is connected to a server from which it obtains data shared with other computers. It is possible, but not common, for some network servers to be used as both a server and a workstation (Windows NT permits this). The term is also used to describe a high-priced PC that uses a proprietary microprocessor and proprietary architecture to create what some call an open system.


Acronym for the Windows Open Services Architecture that is the foundation for such APIs as ODBC, MAPI, and TAPI. Microsoft also develops special vertical-market WOSA APIs for the banking, financial, and other industries.


An acronym for Windows on Win32, a subsystem of Windows NT that allows 16-bit Windows applications to run in protected memory spaces called virtual DOS machines (VDMs).


Any language interpreter or compiler or a database manager built on the dBASE III+ model and incorporating all dBASE III+ commands and functions. Microsoft's FoxPro and Computer Associates' Clipper are xBase dialects.

Yes/No field

A field of a table whose allowable values are Yes (True) or No (False). Yes/No fields were called logical or Boolean fields by Access 95.



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