select top 1 url, count(*) from 表 group by url order by count(*) desc
select url,max(a) 重复数 from (select url,count(*) a from 表 group by url)aa
select url,max(a) 重复数 from (select url,count(*) a from 表 group by url)aa
Limpire(昨夜小楼)你的是正確的
wgzaaa() 呵呵,我是抄你的
呵呵,应该说我们都是“抄”微软的。我看了这以下两句的执行计划: select top 1 name, a = count(*) from syscolumns group by name order by count(*) desc select max(a) from (select name, a = count(*) from syscolumns group by name) aa查询1:相对于54.46% 查询2:相对于45.54%也就是说写成子查询快了将近20%。
select top 1 name, a = count(*) from syscolumns group by name order by count(*) desc
select max(a) from (select name, a = count(*) from syscolumns group by name) aa查询1:相对于54.46%
查询2:相对于45.54%也就是说写成子查询快了将近20%。