结合MySQL JOIN结果中的主键

Question

我有一个返回结果的查询:

Table Units  Table Payments
ID          |  Payment
1003        |  300.00
1003        |  100.00
1004        |  350.00
1005        |  200.00

如何构造查询,使其组合相同的ID,如下所示:

ID      |  Payment
1003    |  400.00
1004    |  350.00
1005    |  200.00

我的查询如下:

SELECT u.id, p.amt FROM units u JOIN payments p ON u.id = p.unit

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我已尝试过SUM()该amt字段,但它只返回一个结果:

ID      |  Payment
1003    |  950.00

Answer 1

SELECT u.id, sum(p.amt) as payment
FROM units u inner JOIN payments p ON u.id = p.unit
group by u.id

DEMO