Data Modeling › Extending Relations › Extended Relations for HORSE File

Extended Relations for HORSE File

The two HORSE Refers to HORSE relations are now shown in an extended form that allows you to specify two extra terms on the relation. Any Refers to or Owned by relation can be extended in this way.

Extending a relation introduces the two following fields:

• For field

  The For field lets you specify the reason for each relation. In this tutorial, you will use this field to distinguish the two HORSE Refers to HORSE relations; in other words, HORSE Refers to HORSE for Dam, and HORSE Refers to HORSE for Sire.

• Sharing field

  The entry in the Sharing field indicates whether the common keys of the two relations are to be shared. *ALL is the default. This field applies only when the referenced file has more than one key field entry. In this tutorial, since the HORSE file has only one key field entry (Horse code), you can take the default.