IZM>select  a.CName, a.nMinball, min(b.ddate) as DMinDate
IZM>from
IZM>(select cName,  min(nBall) as nMinBall
IZM>   from tb_test1
IZM> group by cName
IZM>) a
IZM> join tb_test1 b on (b.cName=a.cname and b.nBall=a.nminball)
IZM>group by  a.CName, a.nMinball
IZM>