popotang

--表名：T 不重复字段：id 另外一个字段 PostTimeselect * from T where PostTime=(select max(PostTime) from T t2 where id=T.id)

 If you set it in the cnf(it may be my.ini file) you will likely need to restart the server. Optionally, that is a dynamic variable and can be SET GLOBAL or SET SESSION from the command line as we