-- 1. c_c 컬럼 일괄 갱신(1회 실행) --
UPDATE store s
SET c_c = (SELECT COUNT(*) FROM com WHERE c_id = s.c_id)
;
-- 2. 트리거 생성 --
CREATE OR REPLACE TRIGGER tr_com_cnt
BEFORE
INSERT OR UPDATE OR DELETE
ON emp
FOR EACH ROW
BEGIN
IF UPDATING OR DELETING THEN
UPDATE store
SET c_c = c_c - 1
WHERE c_id = :OLD.c_id
;
END IF;
IF UPDATING OR INSERTING THEN
UPDATE store
SET c_c = c_c + 1
WHERE c_id = :NEW.c_id
;
END IF;
END;
/