Update data From Other Table

Update one MySQL table with values from another

My customer table looks like:

And the customer_rate table looks like:

I want to update prize in customer with the id from customer_rate based on prize 

Action : customer.prize = customer.qty * customer_rate.prize

The updated table will hopefully look like:

I have a query that works

UPDATE customerINNER JOIN customer_rate ON (customer.cus_id = customer_rate.id)SET customer.prize = customer.qty * customer_rate.prize

add where condition 

UPDATE customerINNER JOIN customer_rate ON (customer.cus_id = customer_rate.id)SET customer.prize = customer.qty * customer_rate.prize where customer.id = 1