Subentry

Example

The above picture shows part of an example database specification. The example contains two entities: an entity Relation and an entity Address. Each Address belongs to a specific Relation. A Relation can have more than one Address.

There is a one-to-many relation between the entities Relation and Address. To express this relation in the DID you can define two Entries; an Entry Relation and an Entry Addresses_of_Relation. If you want to use the Entry Addresses_of_Relation, you need to specify the relation number for which you want to retrieve the addresses. This value is available in the Field Relation_Number of the Entry Relation. In the subentry definition, you can specify that the Field Relation_Number should be used as the actual parameter of the Entry Addresses_of_Relation.

In a Subentry definition, you express the relation between the Entry and the Subentry, by supplying actual parameters for the formal parameters of the Subentry. You can supply Fields or constants for the actual parameters.