设有关系R和S，关系代数表达式R－（R－S）表示的是： -题库考试答案搜索网

设有关系R和S，关系代数表达式R－（R－S）表示的是：

单选题

2021-07-17 23:26

A、<span style=";font-family:宋体;font-size:14px">R<span style="font-family:宋体">∩</span><span style="font-family:Times New Roman">S </span></span></p><p></p>
B、<span style=";font-family:宋体;font-size:14px">R-S</span></p><p></p>
C、<span style=";font-family:宋体;font-size:14px">R<span style="font-family:宋体">∪</span><span style="font-family:Times New Roman">S</span></span></p><p></p>
D、<span style=";font-family:宋体;font-size:14px">R<span style="font-family:宋体">÷</span><span style="font-family:Times New Roman">S</span></span></p><p></p>

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正确答案

A

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标签：计算机网络技术高起专关系型数据库期末考试

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