表结构

mysql> desc dce_his_cs_m_jyhqsj;
+---------+---------------+------+-----+---------+----------------+
| Field   | Type          | Null | Key | Default | Extra          |
+---------+---------------+------+-----+---------+----------------+
| QSJDATE | varchar(20)   | YES  |     | NULL    |                |
| QSJDDDD | varchar(8)    | NO   | PRI | NULL    |                |
| QSJMMMM | varchar(4)    | NO   | PRI | NULL    |                |
| QSJHYBH | varchar(10)   | NO   | PRI | NULL    |                |
| QSJKHBH | varchar(10)   | NO   | PRI | NULL    |                |
| QSJKPJG | decimal(10,2) | YES  |     | NULL    |                |
| QSJKPTM | decimal(20,0) | YES  |     | NULL    |                |
| QSJZGJG | decimal(10,2) | YES  |     | NULL    |                |
| QSJZDJG | decimal(10,2) | YES  |     | NULL    |                |
| QSJSPJG | decimal(10,2) | YES  |     | NULL    |                |
| QSJSPTM | varchar(20)   | YES  |     | NULL    |                |
| QSJCJSL | decimal(10,0) | YES  |     | NULL    |                |
| QSJSKCL | decimal(10,0) | YES  |     | NULL    |                |
| QSJSPCL | decimal(10,0) | YES  |     | NULL    |                |
| QSJBKCL | decimal(10,0) | YES  |     | NULL    |                |
| QSJBPCL | decimal(10,0) | YES  |     | NULL    |                |
| QSJSCCL | decimal(10,0) | YES  |     | NULL    |                |
| QSJBCCL | decimal(10,0) | YES  |     | NULL    |                |
| QSJZCCL | decimal(10,0) | YES  |     | NULL    |                |
| QSJSWTL | decimal(10,0) | YES  |     | NULL    |                |
| QSJBWTL | decimal(10,0) | YES  |     | NULL    |                |
| QSJZWTL | decimal(10,0) | YES  |     | NULL    |                |
| QSJAMPL | decimal(10,2) | YES  |     | NULL    |                |
| QSJZDFD | decimal(10,2) | YES  |     | NULL    |                |
| id      | int(11)       | NO   | UNI | NULL    | auto_increment |
+---------+---------------+------+-----+---------+----------------+
25 rows in set (0.00 sec)

mysql>

SQL

SET SESSION group_concat_max_len = 1000000;

mysql> select id, QSJDDDD, QSJMMMM, QSJCJSL  from dce_his_cs_m_jyhqsj where FIND_IN_SET(id,  (SELECT group_concat(id) as id  from (select substring_index(group_concat(id order by id desc SEPARATOR ','),",",5) as id from dce_his_cs_m_jyhqsj GROUP BY QSJDDDD, qsjmmmm) as b)) order by QSJDDDD, QSJMMMM, QSJCJSL;


mysql> select id, QSJDDDD, QSJMMMM, QSJCJSL  from dce_his_cs_m_jyhqsj where FIND_IN_SET(id,  (SELECT group_concat(id) as id  from (select substring_index(group_concat(id order by id desc SEPARATOR ','),",",5) as id from dce_his_cs_m_jyhqsj GROUP BY QSJDDDD, qsjmmmm) as b)) order by QSJDDDD, QSJMMMM, QSJCJSL;
+-------+----------+---------+---------+
| id    | QSJDDDD  | QSJMMMM | QSJCJSL |
+-------+----------+---------+---------+
|  2577 | 20160909 | 1401    |      14 |
| 10862 | 20160909 | 1401    |      28 |
| 10702 | 20160909 | 1402    |      21 |
| 11142 | 20160909 | 1402    |      35 |
| 11802 | 20160909 | 1402    |      57 |
| 10070 | 20160909 | 1402    |      98 |
|  9238 | 20160909 | 1402    |     120 |
| 11394 | 20160909 | 1403    |       5 |
| 10863 | 20160909 | 1403    |      11 |
| 11803 | 20160909 | 1403    |      14 |
| 11618 | 20160909 | 1403    |      56 |
| 12651 | 20160909 | 1403    |      95 |
| 11395 | 20160909 | 1404    |      53 |
| 12210 | 20160909 | 1404    |      64 |
| 12010 | 20160909 | 1404    |      67 |
| 12652 | 20160909 | 1404    |      89 |
| 12422 | 20160909 | 1404    |     114 |
|  9672 | 20160909 | 1405    |       9 |
| 12653 | 20160909 | 1405    |      22 |
| 11619 | 20160909 | 1405    |      26 |
| 10071 | 20160909 | 1405    |      64 |
| 12423 | 20160909 | 1405    |     118 |

思路：

使用group_concat，然后将group_concat的数据取出前N位（TopN），然后再通过FIND_IN_SET 来获取每个TopN的完整数据即可.