摘要:
select * from information_schema.INNODB_lock_waits;select * from information_schema.INNODB_locks;SHOW PROCESSLIST //查看数据库中表的状态,是否被锁;kill id //杀掉被锁的表... 阅读全文
摘要:
join on 与 where 条件的执行先后顺序: join on 条件先执行,where条件后执行;join on的条件在连接表时过滤,而where则是在生成中间表后对临时表过滤left join、right join、full join、inner join区别: left join:以左... 阅读全文