根据列更改自动编号选择 SQL 中的行

Question

我使用全选语句从表 A 中检索所有值。表 A 示例如下：

+---+----+---+
| a | 23 | X | 
+---+----+---+
| a | 23 | Y |
+---+----+---+
| a | 24 | X |
+---+----+---+
| a | 24 | Y |
+---+----+---+
| b | 24 | X |
+---+----+---+
| b | 24 | Y |
+---+----+---+
| b | 25 | X |
+---+----+---+
| b | 25 | Y |
+---+----+---+
| b | 25 | Z | 
+---+----+---+

出于此查询稍后体育场的目的，我想为第 1 列和第 2 列的每个唯一组合提供一个记录号。例如：

+---+----+---+---+
| a | 23 | X | 1 |
+---+----+---+---+
| a | 23 | Y | 2 |
+---+----+---+---+
| a | 24 | X | 1 |
+---+----+---+---+
| a | 24 | Y | 2 |
+---+----+---+---+
| b | 24 | X | 1 |
+---+----+---+---+
| b | 24 | Y | 2 |
+---+----+---+---+
| b | 25 | X | 1 |
+---+----+---+---+
| b | 25 | Y | 2 |
+---+----+---+---+
| b | 25 | Z | 3 |
+---+----+---+---+

这可能与 SQL 相关吗？如何实现？

Answer 1

您的问题描述将使用dense_rank():

select t.*, dense_rank() over (order by col1, col2)
from t;

您的样本数据建议dense_rank() 和partitition by：

select t.*,
       dense_rank() over (partition by col1, col2 order by col3) as seqnum
from t;

Answer 2

我相信你所需要的只是

SELECT Distinct  
  ROW_NUMBER() OVER(ORDER BY Col1 ASC,Col2 ASC) AS Row_num,
  Col1, Col2
FROM Table1