CREATE TABLE test.dbo.ST_WAS_R (
    ID varchar(50) NOT NULL,
    STCD char(8) NOT NULL,
    TM datetime NOT NULL,
    UPZ numeric(7,3) NOT NULL,
    DWZ numeric(7,3) NOT NULL,
    TGTQ numeric(9,3) NOT NULL,
    SWCHRCD char(1),
    SUPWPTN char(1),
    SDWWPTN char(1),
    MSQMT char(1),
    PRIMARY KEY (ID)
)
GO
INSERT INTO test.dbo.ST_WAS_R(ID, STCD, TM, UPZ, DWZ, TGTQ, SWCHRCD, SUPWPTN, SDWWPTN, MSQMT) VALUES ('1', 'TST00001', '2012-07-17 11:00:00.0', 2.000, 1.000, 1.000, null, null, null, null)
GO
INSERT INTO test.dbo.ST_WAS_R(ID, STCD, TM, UPZ, DWZ, TGTQ, SWCHRCD, SUPWPTN, SDWWPTN, MSQMT) VALUES ('2', 'TST00002', '2012-07-17 00:00:00.0', 1.000, 1.000, 1.000, null, null, null, null)
GO
INSERT INTO test.dbo.ST_WAS_R(ID, STCD, TM, UPZ, DWZ, TGTQ, SWCHRCD, SUPWPTN, SDWWPTN, MSQMT) VALUES ('3', 'TST00001', '2012-07-17 00:00:00.0', 1.000, 1.000, 1.000, null, null, null, null)
GO
INSERT INTO test.dbo.ST_WAS_R(ID, STCD, TM, UPZ, DWZ, TGTQ, SWCHRCD, SUPWPTN, SDWWPTN, MSQMT) VALUES ('4', 'TST00003', '2012-07-18 00:00:00.0', 2.000, 2.000, 2.000, null, null, null, null)
GO
INSERT INTO test.dbo.ST_WAS_R(ID, STCD, TM, UPZ, DWZ, TGTQ, SWCHRCD, SUPWPTN, SDWWPTN, MSQMT) VALUES ('5', 'TST00004', '2012-07-15 00:00:00.0', 3.000, 3.000, 3.000, null, null, null, null)
GO

select a.stcd,tm,upz
from ST_WAS_R a,
 (
select stcd,max(tm) mtm
 from ST_WAS_R
 group by stcd
 )b 
 where a.stcd=b.STCD and a.tm=b.mtm

------解决方案--------------------
SQL code


select a.stcd,
tm,upz
from ST_WAS_R a,
(
select 
stcd,
max(tm) mtm
from 
ST_WAS_R
group by stcd
)b 
 where a.stcd=b.STCD and a.tm=b.mtm