题目内容：
在学生表中要查找所有年龄大于30岁姓王的男同学，应该采用的关系运算是（ ）
A．选择 B．投影
C．联接
D．自然联接
参考答案：
答案解析：
单选题：在学生表中要查找所有年龄大于30岁姓王的男同学，应该采用的关系运算是（ ）
- 题目分类：公共基础知识
- 题目类型：单选题
- 查看权限：VIP
B．投影
C．联接
D．自然联接
B．投影
C．联接
D．自然联接
TheBerlinworkshopconcludedthattherealfigure__________.
TheBerlinworkshopconcludedthattherealfigure__________. A．willinfluencefuturecli
Horse-racingfanscannotbeconsideredsportsmenbecausetheyarespe
Horse-racingfanscannotbeconsideredsportsmenbecausetheyarespectatorswhoseprimary
BasketballinAmericaissopopularwithuniversitiesthatnationwide
BasketballinAmericaissopopularwithuniversitiesthatnationwideuniversitymatchesar
Footballcanbeclassifiedasaspectatorsport.
Footballcanbeclassifiedasaspectatorsport. A．Right B．Wrong C．Notmentioned
Professionalbaseballteamscancontinuetoplayforalongperiodofti
Professionalbaseballteamscancontinuetoplayforalongperiodoftimeinthefallafterthe