how to group by and return sum row in Postgres

问题

I am stuck here. I have row in Postgres like this:

id      amount
a       5000
a       1500
a       500
b       2000
b       1000
c       4000

How is the sql syntax to get result like this?

id      amount
a       7000
b       3000
c       4000

回答1:

SELECT id, SUM(amount) AS amount
FROM yourtable
GROUP BY id

来源：https://stackoverflow.com/questions/8004655/how-to-group-by-and-return-sum-row-in-postgres