stringclear="delete from ex_result where allotid = @allotid and isdelete = 1 and createtime < (select min(createtime) from (select distinct createtime from ex_result where allotid = @allotid and isdelete = 1 order by createtime desc limit 4) t);";
stringclear="delete from ex_result where allotid = @allotid and isdelete = 1 and createtime < (select min(createtime) from (select distinct createtime from ex_result where allotid = @allotid and isdelete = 1 order by createtime desc limit 4) t);";