mysql - 从唯一 id mysql 生成自动增量值

Question

我在一个表中根据id收集不同类型值的相同相似数据:

 +------+---------------+-----------------+----------------+ 
 |  id  |   TransID     |     Amount      |   InsertDate   |
 +------+---------------+-----------------+----------------+ 
 |  1   |      1        |       12        |   19-03-2004   |
 |  2   |      2        |       9         |   20-03-2004   |
 |  3   |      3        |       4         |   21-03-2004   |
 |  4   |      1        |       12        |   22-03-2004   |
 |  5   |      2        |       9         |   23-03-2004   |
 |  6   |      3        |       4         |   24-03-2004   |
 |  7   |      1        |       12        |   25-03-2004   |
 +------+---------------+-----------------+----------------+ 

当我根据 TransID 为 1 选择表时，我希望根据表的 ID 为记录设置一个唯一的自动递增 ID。

如何做到这一点？因此结果将是

 +------+---------------+-----------------+----------------+--------------- 
 |  id  |   TransID     |     Amount      |   InsertDate   | NewGeneratedID
 +------+---------------+-----------------+----------------+----------------- 
 |  1   |      1        |       12        |   19-03-2004   |       1
 |  4   |      1        |       12        |   22-03-2004   |       2
 |  7   |      1        |       12        |   25-03-2004   |       3
 +------+---------------+-----------------+----------------+ ---------------

并且当我只选择表的特定 id 时，例如 id 4，它将给我 NewGeneratedID 2，而不是 1。

 +------+---------------+-----------------+----------------+--------------- 
 |  4   |      1        |       12        |   22-03-2004   |       2
 +------+---------------+-----------------+----------------+ 

Answer 1

您可以根据您的要求使用以下查询

    SELECT t.id,t.TransID ,t.Amount,t.InsertDate ,(@num:=@num+1) AS
 NewGeneratedID  FROM table1 t cross join (SELECT @num:=0) AS dummy 
where t.TransID=1  ORDER BY id;