-- mysql分组排序取前N条记录的最简洁的单条sql。use test;drop table if exists test;create table test ( id int primary key, cid int, author varchar(30)) engine=myisam;insert into test values (1,1,'test1'),(2,1,'test1'),(3,1,'test2'),(4,1,'test2'),(5,1,'test2'),(6,1,'test3'),(7,1,'test3'),(8,1,'test3'),(9,1,'test3'),(10,2,'test11'),(11,2,'test11'),(12,2,'test22'),(13,2,'test22'),(14,2,'test22'),(15,2,'test33'),(16,2,'test33'),(17,2,'test33'),(18,2,'test33');
-- select * from (select cid,author,count(*) as number from test group by cid,author) a where 2>( select count(*) from (select cid,author,count(*) as number from test group by cid,author) b where a.cid=b.cid and a.number<b.number)order by cid,number desc;
