如果有学生表student,sno代表学号,sage代表年龄,则想要得到年龄是18或20的学生学号的SQL语句是()
A. SELECT sno FROM student WHERE sage>18 or sage<20
B. SELECT sno FROM student WHERE sage=18 and sage=20
C. SELECT sno FROM student WHERE sage in (18,20)
D. SELECT sno FROM student WHERE sage between18 and 20
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在SELECT语句中,如果需要显示的内容使用“*”,则表示()
A. 选择任何属性
B. 选择所有属性
C. 选择所有元组
D. 选择主键
查询时若要去掉重复的元组,则在SELECT语句中使用()
All
B. UNION
C. LIKE
DISTINCT
如果有学生表student,sname代表姓名,则想要得到名字中含有“林”的学生所有信息的SQL语句是()
A. SELECT sname = '林' FROM student
B. SELECT sname like '林' FROM student
C. SELECT * FROM student WHERE sname like '%林%‘
D. SELECT * FROM student WHERE sname like '_林_‘
在SQL语句中,与表达式“仓库号 NOT IN ('wh1','wh2')”功能相同的表达式是()
A. 仓库号=’wh1‘ AND 仓库号=’wh2‘
B. 仓库号’wh2‘
C. 仓库号<>’wh1‘ OR 仓库号=’wh2‘
D. 仓库号’wh2‘