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LANSA uses access routes to describe relationships between tables in a database. Access routes are simply descriptions which answer questions such as "How do I access the associated records in table B, given that I have a record from table A?" They have no physical impact on the database. A predetermined join column (PJC) \[previously a predetermined join field (PJF)\] is a special kind of virtual field based on access routes whose value is determined by a field in another table. (Ordinary virtual fields are always based on fields within its own table definition.) |
Objectives:
- To create an access route to define the relationships between the Department and Employee tables.
- To show how to create and maintain predetermined join columns (PJCs).
- To add a calculated predetermined join column to the Department Table based on the Columns in the Employee table.
- To add a table lookup Predetermined Join Column to the Employee Table based on the columns in the Department table.
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