触发器

建表语句：

CREATE TABLE googs(
id INT(12) auto_increment PRIMARY KEY,
gname VARCHAR(12),
gprice DOUBLE
);

CREATE TABLE googs_temp(
id INT(12) auto_increment PRIMARY KEY,
gname VARCHAR(12),
gprice DOUBLE
);

新建触发器：

create trigger tri_stu_delete
BEFORE DELETE
on googs for each row
begin
    INSERT INTO googs_temp(id,gname,gprice) SELECT id,gname,gprice FROM googs WHERE id=old.id;
end;

删除触发器：

DROP TRIGGER tri_stu_delete;

当执行以下语句时，触发器会被触发而自动执行相关操作：

INSERT INTO googs(id,gname,gprice) VALUES(3,'aha',23);
DELETE FROM googs WHERE id=3;