mysql - Minus/Sum a table with itself -

i have table :

id product_property_id product_id amount type 1       1                  145      10    0 2       4                  145      12    0 3       6                  145      13    1 4       23                 147      2     0 5       4                  145      15    1  6       4                  145      2     1    

type :

0: out

1: in

what want :

for example :

product_id 145 product_property_id 4 :

(15+2) - 12 = 5

product_id   product_property_id  new_amout   145              4                  5 

is possible use sql result or have use php instant of ?

if understand correctly, query using conditional aggregation:

select product_id, product_property_id,        sum(case when type = 1 amount                 when type = 0 - amount                 else 0            end) new_amount likethis group product_id, product_property_id;