Establishment of Persistent Relationships with Indexes
Indexes are used to establish persistent relationships between tables in a database. Persistent relationships are relationships between database tables that are stored in the database file and are automatically used as default join conditions in the Query and View Designers. Persistent relationships are also displayed in the Database Designer as lines joining table indexes, and as default relationships when you use the tables in the data environment.
Unlike temporary relationships set with the SET RELATION Command, persistent relationships do not need to be re-created each time you use tables. However, because persistent relationships do not control the relationship between record pointers in tables, you will use both temporary SET RELATION relationships as well as persistent relationships in developing Visual FoxPro applications. For more information on setting persistent relationships, see Developing Databases.
See Also
Setting Temporary Relationships Between Tables | Working with Records | Working with Table Aliases | Working with Multiple Tables | Enhancing the Efficiency of Indexes