PgSql与PHP:关于安排的问题


PgSql with PHP: Issues Regarding Arrangement

假设我有一个类似的表


      a    |     b     |     c     |     d     |     e     |  id |  user_id     |     
---------------------------------------------------------------------------------
  -2.3213  | 9999232342| 0.2099321 |  0.113399 |   -1221   |  1  |43124123321321|
---------------------------------------------------------------------------------
  -3.3213  | 2231232342| 0.3099321 |  0.203799 |   -1231   |  2  |34224123321321|
---------------------------------------------------------------------------------
  -4.3293  | 1111232342| 0.2099321 |  0.203799 |   -1241   |  3  |98787612321321|
---------------------------------------------------------------------------------
  -1.1133  | 2231232342| 0.1099321 |  0.213399 |   -1231   |  4  |76534123321321|
--------------------------------------------------------------------------------
  -4.2469  | 2231232342| 0.6099321 |  0.203399 |   -1261   |  5  |55542333321321|
---------------------------------------------------------------------------------
  -1.1133  | 2231232342| 0.1099321 |  0.103599 |   -1271   |  6  |12454123321321|
---------------------------------------------------------------------------------
  -3.3213  | 2231232342| 0.5099321 |  0.203599 |   -1281   |  7  |23123323321321|

并且每当用户注册时,将插入具有相应值的新行。


---------------------------------------------------------------------------------
  -9.1133  | 2231232342| 0.1099321 |  0.103599 |   -1181   |  8  |23123323321321|

所以。。我可以使用php来排列行吗?它们先按列"a"排列,然后按列"b"排列,再按列"c"排列,等等,按降序排列?


      a    |     b     |     c     |     d     |     e     |  id |  user_id     | 
---------------------------------------------------------------------------------
  -9.1133  | 2231232342| 0.1099321 |  0.103599 |   -1181   |  8  |23123323321321|
---------------------------------------------------------------------------------
  -4.3293  | 1111232342| 0.2099321 |  0.203799 |   -1241   |  3  |98787612321321|
--------------------------------------------------------------------------------
  -4.2469  | 2231232342| 0.6099321 |  0.203399 |   -1261   |  5  |55542333321321|
---------------------------------------------------------------------------------
  -3.3213  | 2231232342| 0.5099321 |  0.203599 |   -1281   |  7  |23123323321321|
---------------------------------------------------------------------------------
  -3.3213  | 2231232342| 0.3099321 |  0.203799 |   -1231   |  2  |34224123321321|    
---------------------------------------------------------------------------------
  -2.3213  | 9999232342| 0.2099321 |  0.113399 |   -1221   |  1  |43124123321321|
---------------------------------------------------------------------------------
  -1.1133  | 2231232342| 0.1099321 |  0.213399 |   -1231   |  4  |76534123321321|
---------------------------------------------------------------------------------
  -1.1133  | 2231232342| 0.1099321 |  0.103599 |   -1271   |  6  |12454123321321|

因此,当我想选择具有最接近值的行时,我可以只选择最接近的行。

我是数据库的新手,如果有人能帮助我,我将不胜感激。谢谢。

要按照您要求的顺序获得结果,可以使用

SELECT * FROM your_table
ORDER BY a ASC, b DESC, c DESC, d DESC, e ASC

请注意,您要求按降序对a进行排序,但您的示例显示了相反的情况,因为a似乎是负数。。。

如果您确实需要降序,即使值为负数,也可以尝试使用ABS函数。

SELECT * FROM your_table
ORDER BY ABS(a) DESC, b DESC, c DESC, d DESC, ABS(e) DESC