SYSFOREIGNKEYS system table

Describes the information specific to foreign key constraints in the current database.

Derby generates a backing index for each foreign key constraint; the name of this index is the same as SYSFOREIGNKEYS.CONGLOMERATEID.

Column Name	Type	Length	Nullability	Contents
CONSTRAINTID	CHAR	36	false	unique identifier for the foreign key constraint (join with SYSCONSTRAINTS. CONSTRAINTID)
CONGLOMERATEID	CHAR	36	false	unique identifier for index backing up the foreign key constraint (join with SYSCONGLOMERATES. CONGLOMERATEID)
KEYCONSTRAINTID	CHAR	36	false	unique identifier for the primary key or unique constraint referenced by this foreign key (SYSKEYS.CONSTRAINTID or SYSCONSTRAINTS. CONSTRAINTID)
DELETERULE	CHAR	1	false	R for NO ACTION (default), S for RESTRICT, C for CASCADE, U for SET NULL
UPDATERULE	CHAR	1	false	R for NO ACTION(default), S for restrict