Question

要怎么统计出不重复的条数?select count(distinct *) from 表

要怎么统计出不重复的条数?

select count(distinct *) from 表

这样不行吗?那得怎么办?

Answer 1

select count(distinct(需要统计不重复的字段)) from 表

Answer 2

Oracle:

select count(*) from (select distinct * from table);

Answer 3

select distinct 列名 from 表名

Answer 4

这样不行.
应这样.select distinct count(*) from 表