A.1NF
B.2NF
C.3NF
D.BCNF
[单选题]F.or relation R where primary key contains multiple attributes,no non-key attribute should be functionally dependent on a part of the primary key. This relation R is at least inA. 1NFB.2NFC.3NFD.BCNF
[单选题]For relation where primary key contains multiple attributes,no non-key attribute should be functionally dependent on a part of primary key.This relation R is at least in (66) .(66) A.3NFB.2NFC.INFD.BCNF
[单选题]F.or relation where primary key contains multiple attributes, no non-key attribute should be functionally dependent on a part of primary key. This relation R is at least in(66).A.3NFB.2NFC.INFD.BCNF
[单选题]For relation where primary key contains multiple attributes, no non-key att
[名词解释] 主码(Primary Key)
[单选题]11. —Where is ________ key to the door?—It’s in my pocket.A.aB.theC./D.an
[单选题]An instruction that uses indrect addressing mustt contain an address of mem
[主观题]在SQL语言中PRIMARY KEY的作用是()。A.定义主码B.定义外部码C.定义处部码的参照表D.确定主码类型
[单选题]在SQL语言中PRIMARY KEY的作用是()。A . 定义主码B . 定义外部码C . 定义处部码的参照表D . 确定主码类型
[单选题]Let R and S be the relation respection respectively:Relation R:A B C Relation S:B C D1 2 3 2 3 46 7 8 2 3 59 7 8 7 8 1The number of tuples that the result of the expression R∞S(Here if natural join of relations R and S) is (69) .(69) A.1B.4C.7D.10