name and sum from 2 different tables

Question

I have 2 tables.
table customer have. id , name , age
table order have . id, customer_id , order_amount , order date.

I want to show all name from customer table and sum of order amount from order table according to customer.

customer_id	Name	age
1	Alice	24
2	Bob	52
3	Carol	45
4	Dave	51

order_id	customer_id	order_amount	order_date
1	2	50	2012-4-5
2	1	27	2012-8-1
3	2	12	2013-5-20
4	4	25	2014-1-25
5	4	30	2014-5-30
6	1	20	2014-6-22

EDIT
I tried this but it gives me only bob and sum of all columns instead of separate sum of customers

SELECT customers.name, SUM(orders.order_amount) FROM `orders` INNER JOIN customers WHERE orders.customer_id = customers.customer_id;

Answer 1

1. Joining condition must be on ON clause, not in WHERE.
2. You must specify for what group the sum must be calculated.

SELECT customers.name, SUM(orders.order_amount) 
FROM `orders` 
INNER JOIN customers ON orders.customer_id = customers.customer_id
GROUP BY customers.name;