Access:abc(数字) SQLServer:abc (数字)
作用:返回数字的绝对值(在猜解汉字的时候会用到)
Access:A between B And C SQLServer:A between B And C
作用:判断A是否界于B与C之间
and exists(Select top 1 * From 用户 order by id)
1.在查询结果中显示列名:
a.用as关键字:select name as ’姓名’ from students order by age
b.直接表示:select name ’姓名’ from students order by age
2.精确查找:
a.用in限定范围:select * from students where native in (’湖南’, ’四川’)
b.between...and:select * from students where age between 20 and 30
c.“=”:select * from students where name = ’李山’
d.like:select * from students where name like ’李%’ (注意查询条件中有“%”,则说明是部分匹配,而且还有先后信息在里面,即查找以“李”开头的匹配项。所以若查询有“李”的所有对象,应该命令:’%李%’;若是第二个字为李,则应为’_李%’或’_李’或’_李_’。)
e.[]匹配检查符:select * from courses where cno like ’[AC]%’ (表示或的关系,与"in(...)"类似,而且"[]"可以表示范围,如:select * from courses where cno like ’[A-C]%’)

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