SYS_REFERENTIAL_CONSTRAINTS

The SYS_REFERENTIAL_CONSTRAINTS table provides information about referential (foreign key) constraints between tables.

Column name Data type Description
CONSTRAINT_CATALOG VARCHAR(128) Top-level container for constraints.
Not used. Always NULL.
CONSTRAINT_SCHEMA VARCHAR(128) Second-level container for constraints.
Not used. Always NULL.
CONSTRAINT_NAME VARCHAR(128) The name of the foreign key constraint.
UNIQUE_CONSTRAINT_CATALOG VARCHAR(128) Top-level container for referenced constraints.
Not used. Always NULL.
UNIQUE_CONSTRAINT_SCHEMA VARCHAR(128) Second-level container for referenced constraints.
Not used. Always NULL.
UNIQUE_CONSTRAINT_NAME VARCHAR(128) The name of the referenced constraint.
MATCH_OPTION VARCHAR(7) Always NONE. Not used.
UPDATE_RULE VARCHAR(9) Always NO ACTION. Not used.
DELETE_RULE VARCHAR(9) Action to perform when a SQL statement violates this referential constraint.
The possible values are:
  • NO ACTION – The DELETE on the referenced primary key does not affect the foreign key.
  • CASCADE – The DELETE on the referenced primary key causes cascading deletes for all related records.
OBJECT_CATALOG VARCHAR(128) Top-level container for the table to which this foreign key belongs.
Not used. Always NULL.
OBJECT_SCHEMA VARCHAR(128) Second-level container for the table to which this foreign key belongs.
Not used. Always NULL.
OBJECT VARCHAR(128) The name of the table to which this foreign key belongs.
FIELD VARCHAR(128) The foreign key column.
RELATED_OBJECT_CATALOG VARCHAR(128) Top-level container for the referenced table.
Not used. Always NULL.
RELATED_OBJECT_SCHEMA VARCHAR(128) Second-level container for the referenced table.
Not used. Always NULL.
RELATED_OBJECT VARCHAR(128) The name of the referenced table.
RELATED_FIELD VARCHAR(128) The primary key column referenced by the foreign key.