SYNOPSIS ALTER TABLE [ ONLY ] name [ * ] ADD [ COLUMN ] column type [ column_constraint [ ... ] ] ALTER TABLE [ ONLY ] name [ * ] DROP [ COLUMN ] column [ RESTRICT | CASCADE ] ALTER TABLE [ ONLY ] name [ * ] ALTER [ COLUMN ] column { SET DEFAULT expr
Nearly every one have used the Multiplication Table. But could you find out the k-th smallest number quickly from the multiplication table? Given the height m and the length n of a m * n Multiplication Table, and a positive integer k, you need to ret
为了修复节点表某批次数据的用户数据,做出了以下尝试: , name , , )); 执行:[Err] 1093 - You can't specify target table 'zs_work_approval_node' for update in FROM clause 百度查询提示得知: update语句中包含的子查询的表和update的表为同一张表时,报错:1093-You can’t specify target table for update in FROM clause mys
在修改/增加表字段的时候,发现很慢, show processlist; 时, Waiting for table metadata lock 能一直锁很久. 官网的一段话,可以理解下 http://dev.mysql.com/doc/refman/5.5/en/metadata-locking.html 8.10.4. Metadata Locking MySQL 5.5.3 and up uses metadata locking to manage access to objects (t