MySQL基于第二个“公共”字段对一个字段求​​和

Question

不是SQL人，所以我处于绑定状态，所以我会保持这个简单

+--------------+------------------------+
| RepaymentDay | MonthlyRepaymentAmount |
+--------------+------------------------+
|            3 |               0.214847 | 
|           26 |               0.219357 | 
|           24 |               0.224337 | 
|            5 |               0.224337 | 
|           18 |               0.224337 | 
|           28 |               0.214847 | 
|            1 |               0.224337 | 
|           28 |               0.327079 |
+--------------+------------------------+

我正在寻找一个可以提供类似内容的查询

+--------------+------------------------+
| RepaymentDay | MonthlyRepaymentAmount |
+--------------+------------------------+
|            1 |               0.224337 | 
|            3 |               0.214847 | 
|            5 |               0.224337 | 
|           18 |               0.224337 | 
|           24 |               0.224337 | 
|           26 |               0.219357 | 
|           28 |               0.541926 | 
+--------------+------------------------+

I.e如果有多个记录具有相同的'RepaymentDay'值，则将'MonthlyRepaymentAmount'的值相加。

我可以使用perl或python在外部执行，没有问题，但我想尝试更熟悉SQL。 有什么想法吗？

Answer 1

SELECT RepaymentDay, SUM(MonthlyRepaymentAmount) AS MonthlyRepaymentAmount
FROM YourTable
GROUP BY RepaymentDay
ORDER BY RepaymentDay

Answer 2

按RepaymentDay从table_name组中选择RepaymentDay，sum（MonthlyRepaymentAmount）;