MySQL之触发器

callmehansea2024-07-16 18:39

1，创建表

CREATE TABLE Product (
    Id INT(10) NOT NULL AUTO_INCREMENT PRIMARY KEY,
    Name VARCHAR(20) NOT NULL,
    Function VARCHAR(50),
    Company VARCHAR(20) NOT NULL,
    Address VARCHAR(20)
);

CREATE TABLE Operate (
    Op_id INT(10) NOT NULL AUTO_INCREMENT PRIMARY KEY,
    Op_type VARCHAR(20) NOT NULL,
    Op_time VARCHAR(20) NOT NULL
);

2，创建触发器

DELIMITER //
CREATE TRIGGER product_bf_insert
BEFORE INSERT ON Product
FOR EACH ROW
BEGIN
    INSERT INTO Operate (Op_type, Op_time) VALUES ('Insert', NOW());
END; //
DELIMITER ;

DELIMITER //
CREATE TRIGGER product_af_update
AFTER UPDATE ON Product
FOR EACH ROW
BEGIN
    INSERT INTO Operate (Op_type, Op_time) VALUES ('Update', NOW());
END; //
DELIMITER ;

DELIMITER //
CREATE TRIGGER product_af_del
AFTER DELETE ON Product
FOR EACH ROW
BEGIN
    INSERT INTO Operate (Op_type, Op_time) VALUES ('Delete', NOW());
END; //
DELIMITER ;

3，执行操作

INSERT 操作

INSERT INTO Product (Name, Function, Company, Address) VALUES ('Product A', 'Feature X', 'Manufacturer Y', 'Location Z');

UPDATE 操作

UPDATE Product SET Function = 'New Feature' WHERE Id = 1;

DELETE 操作

DELETE FROM Product WHERE Id = 1;

删除触发器

DROP TRIGGER IF EXISTS product_bf_insert;
DROP TRIGGER IF EXISTS product_af_update;