SQL查询，其中SUM包含where子句

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"   |

我想做的是获取一个SQL查询，它给出了如下所示的输出：

|  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"   |

这主要是按日期和来源分组，然后对金额求和。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