现有表user，字段：userid，username, salary, deptid，email; 表department，字段：deptid, deptname;下面（）应采用检查约束来实现。 -题库考试答案搜索网

现有表user，字段：userid，username, salary, deptid，email; 表department，字段：deptid, deptname;下面（）应采用检查约束来实现。

单选题

2021-09-01 20:33

A、若department中不存在deptid为2的纪录，则不允许在user表中插入deptid为2的数据行。
B、若user表中已经存在userid为10的记录，则不允许在user表中再次插入userid为10的数据行。
C、User表中的salary（薪水）值必须在1000元以上。
D、若User表的email列允许为空，则向user表中插入数据时，可以不输入email值。

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正确答案

C

试题解析

标签：联大河南财经政法大学数据库基础与应用

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