MySQL 表关联插入：根据条件控制数据插入

CREATE TABLE aaa ( id INT PRIMARY KEY AUTO_INCREMENT, user VARCHAR(50), value INT );

CREATE TABLE bbb ( id INT PRIMARY KEY AUTO_INCREMENT, user VARCHAR(50), value INT, FOREIGN KEY (user) REFERENCES aaa(user) );

INSERT INTO aaa (user, value) VALUES ('user1', 1); INSERT INTO aaa (user, value) VALUES ('user2', 0);

INSERT INTO bbb (user, value) SELECT user, 1 FROM aaa WHERE user='user1' AND value=1; --成功插入一行

INSERT INTO bbb (user, value) SELECT user, 1 FROM aaa WHERE user='user2' AND value=1; --插入失败，因为aaa中的值为0