()has the distinct advantage in the terms of fast delivery and enjoy the lowest ratio o
A.Air transport
B.Water transport
C.Land transport
D.Common transport
A.Air transport
B.Water transport
C.Land transport
D.Common transport
A.Adjacent links should not have the same VLANID; non-adjacent links can share the same VLANID.
B.Adjacent links can have the same VLANID; non-adjacent links should not share the same VLANID.
C.All links share the same VLANID.
D.Each link has a distinct VLANID.
A.SELECTCOUNT(DISTINCT借书证号)FROM借阅WHERE借书证号IN(SELECT借书证号FROM读者WHERE单位="ABC")
B.SELECTSUM(DISTINCT借书证号)FROM借阅WHERE借书证号IN(SELECT借书证号FOR借阅WHERE单位="ABC")
C.SELECTCOUNT(DISTINCT借书证号)FROM借阅WHERE借书证号IN(SELECT借书证号FROM借阅WHERE单位="ABC")
D.SELECTSUM(DISTINCT借书证号)FROM借阅WHERE借书证号IN(SELECT借书证号FROM读者WHERE单位="ABC")
A.表包含TEXT或者BLOB列
B.表包含char列
C.GROUPBY或者DISTINCT子句中包含长度大于512字节的列
D.使用UNION或者UNIONALL时.SELECT子句中包含大于512字节的列