SELECT period,idCnt FROM MyTb WHERE ((idCnt - 1) IN (SELECT idCnt FROM MyTb WHERE name ='book' AND idCnt>=44905)) AND idCnt>=44905DBCC FREEPROCCACHE DBCC DROPCLEANBUFFERSSELECT period,idCnt FROM MyTb WHERE ((idCnt - 1) IN (SELECT idCnt FROM MyTb WHERE name = (SELECT name FROM MyTb WHERE idCnt =(SELECT MAX(idCnt) FROM MyTb ))) AND idCnt>=44905) AND idCnt>=44905 试试
rs=stmt.executeQuery(ls_select_sql);用上面的替代stmt = dbConn.prepareStatement(ls_select_sql);
居然两者的执行时间就差不多了,而且达到了正常的直接写name=‘book’快什么原因呢 ????
SELECT period,idCnt FROM MyTb WHERE
((idCnt - 1) IN (SELECT idCnt FROM MyTb WHERE name ='book' AND idCnt>=44905)) AND idCnt>=44905DBCC FREEPROCCACHE
DBCC DROPCLEANBUFFERSSELECT period,idCnt FROM MyTb WHERE
((idCnt - 1) IN (SELECT idCnt FROM MyTb WHERE name =
(SELECT name FROM MyTb WHERE
idCnt =(SELECT MAX(idCnt) FROM MyTb ))) AND idCnt>=44905) AND idCnt>=44905
试试
rs=stmt.executeQuery(ls_select_sql);用上面的替代stmt = dbConn.prepareStatement(ls_select_sql);
居然两者的执行时间就差不多了,而且达到了正常的直接写name=‘book’快什么原因呢 ????