加入兩個表（含計算）

Question

比方說，我在MySQL的這兩個表：

1. table_name的

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 

如何有SQL查詢看，這樣我就可以得到這樣的表格：

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

Answer 1

嘗試使用GROUP BY關鍵字

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 

希望這個作品

Answer 2

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