求高手,帮忙优化一个语句
想在B表中找出符合条件的UniqueNumber,并在A表中删除该UniqueNumber对应的记录,
strSQLDelete = "Delete from TblA where UniqueNumber IN ( ";
strSQLDelete += "SELECT UniqueNumber " ;
strSQLDelete += " FROM TblA H ";
strSQLDelete += " LEFT OUTER JOIN TblB M ";
strSQLDelete += " ON (H.onDate = M.onDate) and (H.roundNo = M.roundNo) and (H.sampleNo = ";
strSQLDelete += " M.sampleNo) and (H.orderType = M.orderType) and (";
strSQLDelete += GetSelectedMethodCode(); 此处是N个条件,如:1 OR 2 OR 3 ... OR 60
strSQLDelete += " ) WHERE M.onDate IS NULL) ";
在双核机器上删除需要半分钟,实在太慢了,本人刚接触SQL,希望高手能帮忙优化一下,最好控制在5秒以内。