how to add temp column in mysql table which contains max value of a respective group

Question

I want to do something Like this :

Current table :

Name	coupon_price
John	10
Sammy	20
Ben	100
Joseph	120
John	90
Joseph	20
John	50
Sammy	30

while selecting data in query (Sum of Coupon price for each customer) without loosing the actual rows of customers, i want to have this expected result :

Name	coupon_price	total_coupon_amount
John	10	150
Sammy	20	50
Ben	100	100
Joseph	120	140
John	90	150
Joseph	20	140
John	50	150
Sammy	30	50

Goal is to select the sum of coupon prices for distinct customer, not alter the rows so we cannot use group by in main query, also the total coupon price should be same for all similar names.

Edit : I don't want to modify the table, I want this column while running select query, run time temp column.

Answer 1

SELECT Name,
       coupon_price,
       total_coupon_amount 
FROM t1 
JOIN (SELECT Name, 
             SUM(coupon_price) AS total_coupon_amount 
      FROM t1 
      GROUP BY Name) r2 USING (Name);

You create the sum in a subquery and join the two.

You should/could put also at the ORDER BY what you want

If you want a view just out CREATE VIEW before