上面只有这两句是对的,其它全错!
select item,price from tb_test where (item,drq) in (select item,max(drq) from tb_test group by item);
和
SELECT * FROM TEST T WHERE (T.ITEM,T.DATE1) IN (SELECT ITEM,MAX(DATE1) FROM TEST GROUP BY ITEM)
不过这也太慢了吧! 应该是下面这句:
select item,price,mydate from test t where mydate=(select max(mydate) from te
st where item=t.item);