Example 3: Resolving the Foreign Key Using a Special User Key

A typical example of using a special user key (rather than the normal U1 user key) to resolve foreign keys is the use of the special user key S_ADDR_PER:Communications in the resolution of foreign keys to S_ADDR_PER. This special user key contains only the column ADDR_NAME, in contrast to (ADDR_NAME, PER_ID) in the U1 user key.

The mapping of S_ORDER.BL_ADDR_ID in EIM_ORDER, for example, uses the special user key S_ADDR_PER:Communications instead of the U1 user key. Mappings of all foreign keys to S_ADDR_PER use this special user key instead of the U1 user key.