A.int B.smallint C.tinyint D.bit
A.外模式 B.内模式 C.模式 D.其他
A.SELECT Sno, COUNT(*) FROM SC GROUP BY Sno B.SELECT Sno FROM SC GROUP BY Sno WHERE COUNT(*)> 3 C.SELECT Sno FROM SC GROUP BY Sno HAVING COUNT(*)> 3 D.SELECT Sno FROM SC GROUP BY Sno
A.Connection B.Update C.Command D.Recordset
A.能够描述并发数据 B.能够真实地模拟现实世界 C.容易被业务人员理解 D.能够方便地在计算机上实现