A.關(guān)系 B.數(shù)據(jù)表 C.數(shù)據(jù)集 D.數(shù)據(jù)源
A.DISTINCT BY B.ORDER BY C.GROUP BY D.CRATER BY
A.[姓名]Is Null B.[姓名]Not Is Null C.[姓名]Like Is Null D.[姓名]OR Is Null