UPDATE posts SET SpareFlag=0 WHERE Id IN( SELECT Id FROM posts WHERE CloseFlag=0 AND LockFlag=0 GROUP BY PosterUid HAVING COUNT(PosterUid)=1 );
上面这样的写法,数据库会提示1093错误;正确写法如下:
UPDATE posts SET SpareFlag=0 WHERE Id IN( SELECT b.Id FROM (SELECT Id FROM posts WHERE CloseFlag=0 AND LockFlag=0 GROUP BY PosterUid HAVING COUNT(PosterUid)=1) AS b );
即,为查询条件建个临时表,这样就解决问题了。