[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]F.or relation R where primary key contains multiple, 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]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 att
[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
[主观题]在SQL中可以使用PRIMARY KEY子句对完整性( )
[单选题]如果已经建立主关键字为仓库号的仓库关系,现在用如下命令建立职工关系CREATE TABLE 职工(职工号 C(5) PRIMARY KEY;仓库号 C
[单选题]如果已经建立了主关键字为仓库号的仓库关系,现在用如下命令建立职工关系CREATE TABLE职工(职工号C(5)PRIMARY KEY,仓库号C(5)