分开查询
先查询id
select CAST(group_concat(ids) AS CHAR(10000) CHARACTER SET utf8) as iid
from (select SUBSTRING_INDEX(group_concat(id ORDER BY 字段),',',4) as ids from `table` group by 字段) as val
在根据id查询数据
SELECT * FROM table where id in ($id)
这种也是可以的
select 字段,substring_index(group_concat( concat(字段,':',字段) order by 字段 desc separator '|'),'|',5) from table group by 字段;
具体看情况
DELETE FROM xxx WHERE id NOT IN(SELECT id FROM (SELECT MAX(b.id) AS id FROM xxx b GROUP BY b.xxxx) b)
