题目内容

单选题 Each row in a relation is called ().

A. an attribute
B. a tuple
C. a union
D. an attitude

查看答案

搜索结果不匹配？点我反馈

更多问题

单选题 If a relation has five rows, then its () is five.

A. difference
B. cardinality
C. duplicity
D. relativity

单选题（）is a declarative language used on relational databases.

A. PDQ
B. SQL
C. LES
D. PBJ

填空题 A DBMS users can be or programs.

填空题 In the history of database design, three models have been in use: the model, the model, themodel.