23 Trigger 1 CREATE TRIGGER 2 DROP TRIGGER

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23장. Trigger 1. CREATE TRIGGER 구문 2. DROP TRIGGER 구문 3. 트리거 사용하기 12/24/2021

23장. Trigger 1. CREATE TRIGGER 구문 2. DROP TRIGGER 구문 3. 트리거 사용하기 12/24/2021 쉽게 배우는 My. SQL 5. x 1

CREATE TABLE test 1(a 1 INT); CREATE TABLE test 2(a 2 INT); CREATE TABLE

CREATE TABLE test 1(a 1 INT); CREATE TABLE test 2(a 2 INT); CREATE TABLE test 3(a 3 INT NOT NULL AUTO_INCREMENT PRIMARY KEY); CREATE TABLE test 4( a 4 INT NOT NULL AUTO_INCREMENT PRIMARY KEY, b 4 INT DEFAULT 0 ); DELIMITER | CREATE TRIGGER testref BEFORE INSERT ON test 1 FOR EACH ROW BEGIN INSERT INTO test 2 SET a 2 = NEW. a 1; DELETE FROM test 3 WHERE a 3 = NEW. a 1; UPDATE test 4 SET b 4 = b 4 + 1 WHERE a 4 = NEW. a 1; END; | DELIMITER ; INSERT INTO test 3 (a 3) VALUES (NULL), (NULL), (NULL), (NULL); INSERT INTO test 4 (a 4) VALUES (0), (0), (0), (0); 12/24/2021 쉽게 배우는 My. SQL 5. x 5