Exam C-ABAPD-2309 Topic 6 Question 32 Discussion

The purpose of a foreign key relationship between two tables in the ABAP Dictionary is to ensure the integrity of data in the corresponding database tables. A foreign key relationship defines a logical link between a foreign key table and a check table, where the foreign key fields of the former are assigned to the primary key fields of the latter. This means that the values entered in the foreign key fields must exist in the check table, otherwise the system will reject the entry. This way, the foreign key relationship prevents the insertion of invalid or inconsistent data in the database tables.
A foreign key relationship also serves to document the relationship between the two tables in the ABAP Dictionary, but this is not its primary purpose. A foreign key relationship does not necessarily create a corresponding foreign key relationship in the database, as this depends on the database system and the settings of the ABAP Dictionary. Some database systems do not support foreign keys at all, while others require additional steps to activate them. Therefore, the foreign key relationship in the ABAP Dictionary is mainly a logical concept that is enforced by the ABAP runtime environment.
References: Foreign Keys (SAP Library - ABAP Dictionary), Foreign Keys (SAP Library - BC - ABAP Dictionary)
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