Ansicht
Dokumentation

ABENDDIC_DATABASE_TABLES_CHECKTAB - DDIC DATABASE TABLES CHECKTAB

- Check Table

Table fields of a DDIC database table whose data type is determined by a DDIC data element can be assigned a check table. Here, the value table of any DDIC domain of the data element is used as a default value. A table field to which a check table is assigned is called a foreign key field and becomes a part of the foreign key of the table. The table itself becomes a foreign key table. The primary key of the check table is the foreign key of the foreign key table. Each key field of the check table corresponds to a field in the foreign key table. Here, the corresponding field pairs must have the same data type.

Notes

• Fields whose data type is specified directly cannot be assigned a check table.

• As long as a DDIC database table is a check table, none of its key fields can be deleted and the order of the key fields cannot be modified.

• As long as a DDIC database table is a check table, its primary key can be expanded later only by appending new key fields to its end. The existing foreign keys then automatically become generic with respect to the new key fields.

• A client field cannot be inserted later into an existing check table.

• A special column can be used to flag obsolete data in check tables.