mysql for update 如果事务一直没有提交会不会这表数据一直锁在那里

Question

mysql for update 锁住了一条或多条数据，或者是整个表 如果事务一直没有提交（比如服务器挂掉了）会不会这表数据一直锁在那里

Answer 1

No. After the client connection is disconnected, the lock will be automatically released.

Client 1

set AUTOCOMMIT = 0;
BEGIN；
SELECT * FROM articles WHERE id=1 FOR UPDATE ;

Client 2

set AUTOCOMMIT = 0;
BEGIN；
SELECT * FROM articles WHERE id=1 FOR UPDATE ;

At this time, client 2’s query will be stuck. Until client 1 commit or rollback . However, if client 1 directly closes the window and disconnects, client 2 can also directly obtain the lock. Explain that when the client disconnects, the lock will be automatically released. commit 或 rollback 。但是，如果客户端1直接关闭窗口断开连接，客户端2也能直接拿到锁。说明客户端断开时，会自动释放锁。

那么问题来了，客户端1断开连接后，是自动 rollback

Then the question is, after client 1 disconnects, does it automatically rollback? 🎜