ALTER TABLE TBAJUSTE_APUR_IPI
ADD ID INTEGER;

CREATE SEQUENCE GTBAJUSTE_APUR_IPI;

UPDATE TBAJUSTE_APUR_IPI T SET
    T.ID = GEN_ID(GTBAJUSTE_APUR_IPI, 1)
WHERE
    T.ID IS NULL;

ALTER TABLE TBAJUSTE_APUR_IPI ALTER ID SET NOT NULL;

/* 
ALTER TABLE TBAJUSTE_APUR_IPI
ADD CONSTRAINT PK_TBAJUSTE_APUR_IPI
PRIMARY KEY (ID); 
*/

SET TERM ^ ;

CREATE OR ALTER TRIGGER TTBAJUSTE_APUR_IPI_B01I FOR TBAJUSTE_APUR_IPI
ACTIVE BEFORE INSERT POSITION 0
AS
BEGIN
  IF (NEW.ID IS NULL) THEN
    NEW.ID = GEN_ID(GTBAJUSTE_APUR_IPI, 1);
END
^

SET TERM ; ^