oracle Group by 分组查询后，分页

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1.分页查询 select count(*) times,title from menulog group by title order by count(*) desc 

2, 生成一个带rn字段的表tableRN=(SELECT rownum as rn, a.* FROM (select count(*) times,title from menulog group by title order by count(*) desc ) a)

3  select  * from  tableRN where rn between 0 and 6

select * from(SELECT rownum as rn, a.* FROM (select count(*) times,title from menulog group by title order by count(*) desc ) a) 

where rn between 0 and 6

 

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select count(*) times,max(url), title from menulog b group by title order by count(*) desc  

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今天看公司的代码，看到很多max或者sum某个字段的值这样无意义的写法，一开始很疑惑这样写是为了什么。

后来了解到，原来和后面使用到的group by有关，只要select的，不调用聚合函数的，一定要出现在group by里，而group by里出现的，不一定在出现在select里。

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