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Self Joins

A self join enables you to join a table to itself. This is often done so that information in a single table can appear to exist in two separate tables. A classic example is seen with employees and supervisors. Two fields are included in the Employees table; one field includes the EmployeeID of the employee being described in the record, and the other field specifies the EmployeeID of the employee's supervisor. If you want to see a list of employee names and the names of their supervisors, you'll need to use a self join.

To build a self-join query, follow these steps:


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