Common uses of joining or relating

A common use of joining or relating is to match records in a transaction table with those in a master table. For example:

Because ACL joins are predominantly many-to-one joins, and ACL relations are always many-to-one relations, the transaction table should usually be the primary or parent table, and the master table the secondary or child table. Multiple transactions (‘many’), such as a number of days of T&E claims, can be joined or related to a single master record (‘one’), such as a T&E limit. Carefully identify your primary/parent and secondary/child tables because results can differ if you reverse the order. As a general rule, if you want to analyze all the records in a table, that table should be the primary or parent table.

Another common use of joining or relating is to compare the contents of two files. For example:

Related concepts
Joining versus relating
About joining tables
About relating tables

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