MYSQL: adding values based on string values in other cells

Question

Let's say we have table like this:

Car	Colour	Red colour car price	Black colour car price
Brand1	Red	20000	25000
Brand2	Red	32000	34000
Brand2	Black	32000	34000
Brand2	Black	32000	34000

There is set prices for 2 different colours for each car brand. Prices are different for each brand. I need to find how much different brand cars cost in total. So, for Brand1 it'll be 20000 and for Brand2 32000 + 34000 + 34000 = 100000

Final table should look like this:

Car	Total cost
Brand1	20000
Brand2	100000

I don't know how to do that and any help is welcome.

Answer 1

Hmmm. . . I think you want conditional aggregation:

select car,
       sum(case when color = 'Red' then red_color_price
                when color = 'Black' then black_color_price
           end)
from t
group by car;