mysql选择上一条、下一条数据记录，排序上移、下移、置顶_MySQL

1.功能需要

2设置思路

设置一个rank为之间戳，通过选择上移，就是将本记录与上一条记录rank值交换，下移就是将本条记录与下一条记录rank值交换，置顶就是将本记录与rank值最小的记录交换

3.表数据结构

SELECT * FROM user ORDER BY rank ASC

+----+------+---------+
| ID | rank | name |
+----+------+---------+
| 1 | 1 | admin1 |
| 2 | 2 | admin2 |
| 3 | 3 | admin3 |
| 4 | 4 | admin4 |
| 5 | 5 | admin5 |
| 6 | 6 | admin6 |
| 7 | 7 | admin7 |
| 8 | 8 | admin8 |
| 9 | 9 | admin9 |
| 10 | 10 | admin10 |
| 11 | 11 | admin11 |
| 12 | 12 | admin12 |
+----+------+---------+

4.选择上一行

select * from user where id <3 or id=(SELECT MIN(id) from user) order by id desc limit 1

+----+------+--------+
| ID | rank | name |
+----+------+--------+
| 2 | 2 | admin2 |
+----+------+--------+
1 row in set (0.00 sec)

5.当id=1时

mysql> select * from user where id <1 or id=(SELECT MIN(id) from user) order by id desc limit 1;
+----+------+--------+
| ID | rank | name |
+----+------+--------+
| 1 | 1 | admin1 |
+----+------+--------+
1 row in set (0.00 sec)

6.选择下一行

mysql> select * from user where id > 3 OR ID=(SELECT MAX(ID) FROM user) ORDER BY id ASC LIMIT 1;
+----+------+--------+
| ID | rank | name |
+----+------+--------+
| 4 | 4 | admin4 |
+----+------+--------+
1 row in set (0.00 sec)

7.当id为最大值时

mysql> select * from user where id > 12 OR ID=(SELECT MAX(ID) FROM user) ORDER BY id ASC LIMIT 1;
+----+------+---------+
| ID | rank | name |
+----+------+---------+
| 12 | 12 | admin12 |
+----+------+---------+
1 row in set (0.00 sec)