连接两个表（带计算）

Question

假设我在 MySQL 中有这两个 table：

1。 table_name

name
------
Max     
John
Sarah
Peter

2。 table_money

name   | amount     | month
-------------------------------
Max    | 100        | January
Sarah  | 90         | January
Max    | 100        | February
Sarah  | 90         | February
Peter  | 90         | February

如何查看 SQL 查询，以便我可以得到这样的 table：

name  | total (amount * #month)
-------------------------------
Max   | 200
Sarah | 180
Peter | 90

Answer 1

尝试按关键字分组

SELECT table_name.name,sum(table_money.amount) as total
FROM table_name JOIN table_money
on table_name.name = table_money.name
GROUP BY table_money.name

希望这有效

Answer 2

Try this
SELECT name,sum(amount) Total 
FROM table_money 
GROUP BY name