SUM 包含 where 子句的 SQL 查询

Question

我有一个如下所示的数据库结构:

|  Date  | Amount | Source |
|02/02/02| 100    |  "A"   |
|02/02/02| 300    |  "B"   |
|05/05/02| 200    |  "A"   |
|05/05/02| 700    |  "B"   |
|07/05/02| 200    |  "C"   |
|07/05/02| 700    |  "C"   |

我想要做的是获得一个 SQL 查询，它给我如下所示的输出:

|  Date  | Amount | Source |
|02/02/02| 100    |  "A"   |
|02/02/02| 300    |  "B"   |
|05/05/02| 200    |  "A"   |
|05/05/02| 700    |  "B"   |
|07/05/02| 900    |  "C"   |

本质上是按日期和来源分组，然后求和。我该怎么做？

Answer 1

here你可以看到你基本上需要:

SELECT Date, SUM(Amount) AS Total_Amount, Source FROM my_table GROUP BY Date, Source