mysql想实现两列表格相邻行内容互换报错

select name,id from 表名

如果更改表结构：

alter table 表名 modify column id int auto_increment after name

比如：

#建立测试表 t1

mysql>create table t1(id int auto_increment,name varchar(20),primary key(id))engine=innodb,default charset=utf8

Query OK, 0 rows affected (0.11 sec)

#插入3条数据

mysql>insert into t1(name) values ("aa"),("bb"),("cc")

Query OK, 3 rows affected (0.00 sec)

Records: 3 Duplicates: 0 Warnings: 0

mysql>select * from t1

+----+------+

| id | name |

+----+------+

| 1 | aa |

| 2 | bb |

| 3 | cc |

+----+------+

3 rows in set (0.00 sec)

#结果集中排列name到id前

mysql>select name,id from t1

+------+----+

| name | id |

+------+----+

| aa | 1 |

| bb | 2 |

| cc | 3 |

+------+----+

3 rows in set (0.00 sec)

#改变表结构，使name在id前

mysql>alter table t1 modify column id int auto_increment after name

Query OK, 3 rows affected (0.19 sec)

Records: 3 Duplicates: 0 Warnings: 0

mysql>select * from t1

+------+----+

| name | id |

+------+----+

| aa | 1 |

| bb | 2 |

| cc | 3 |

+------+----+

3 rows in set (0.00 sec)

mysql>desc t1

+-------+-------------+------+-----+---------+----------------+

| Field | Type | Null | Key | Default | Extra |

+-------+-------------+------+-----+---------+----------------+

| name | varchar(20) | YES | | NULL | |

| id | int(11) | NO | PRI | NULL | auto_increment |

+-------+-------------+------+-----+---------+----------------+

1 先得到用户的两个相邻点的经纬度。

先把表处理成带唯一标识字段的(uid)，便于下一步取出经纬度。表T(uid,user_id,latitude,longitude)

生成一个视图，取得两个相邻点经纬度。

create view vt as

select A.user_id,A.latitude latitudeA,A.longitude longitudeA

,B.latitude latitudeB,B.longitude longitudeB

from T A inner join T B

ON A.user_id=B.user_id AND A.uid<B.uid

2 找个经纬度计算距离的公式（据说有好几种算法），在查询中动态生成或编程中计算生成

select user_id, acos( cos(latitudeA)*cos(longitudeA) * cos(latitudeB)*cos(longitudeB)

+cos(latitudeA)*sin(longitudeA) * cos(latitudeB)*sin(longitudeB)

+sin(latitudeA)*sin(latitudeB)) dis

from vt