• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint

Binary Objects

Binary objects epitomize complex attributes—of all the complex types, these are the most complex. Binary objects are often called BLOB values, both as an acronym (Binary Large OBject), and because the term is irresistibly onomatopoeic. In essence, a BLOB is a chunk of bits that are not interpreted by the data store. SQL Server supports BLOB values with the binary and varbinary data types. Microsoft Jet stores them as OLE Objects. The contents of columns of this type can contain any kind of data, but are typically used for images or formatted text. To the database engine, they're just bytes.

Many designers prefer not to store BLOB values in the database, storing the location and file name instead. The justification is that database engines are notoriously inefficient at storing this kind of data. SQL Server is better than most (Microsoft Jet is pretty hopeless, for example, since it insists on trying to interpret the data), but even if you're using SQL Server or MSDE as a data engine, storing a reference to an external file rather than the object itself is still a justifiable approach.


PREVIEW

                                                                          

Not a subscriber?

Start A Free Trial


  
  • Creative Edge
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint