ALTER TABLE TABLE1
ADD CONSTRAINT FK_TABLE1_DIR
FOREIGN KEY (ID_DIR)
REFERENCES DIR(ID)
ON UPDATE CASCADE

Невозможно подтвердить транзакцию:
violation of FOREIGN KEY constraint "".
violation of FOREIGN KEY constraint "FK_TABLE1_DIR" on table "TABLE1".
Foreign key reference target does not exist.
Problematic key value is ("ID_DIR" = NULL).