sQL 数据库如何获取一列的非重复值

比如：

cc列如下:

xxx

vvv

bbbb

ccc

xxx

想只要显示

xxx

vvv

bbbb

ccc

解决方法如下：

如果得到所有值不重复。

select cc from tablename group by cc

或

select distinct cc form tablename

如果得到没有重复的所有制，

select cc from tablename group by cc

minus

select cc

from(

select cc,count(*) from tablename group by cc having count(*)>1) A

Adodc1.RecordSource = "select top 1 * from 学生表 order by rnd(id)"，随机1个

Adodc1.RecordSource = "select top 10 * from 学生表 order by rnd(id)"，随机10个

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