MySQL multiplication

Question

I am trying to do a multiplication operation in MySQL. I have the following table called vehicul:

id car_type car_model  number price  car_id
1    audi    <model1>    2     320     1
2    audi    <model2>    4     100     1
3    bmw     <model1>    3     240     2
4    bmw     <model2>    6     500     2
5    bmw     <model3>    1     400     2

I have this command:

SELECT car_type, sum(price) FROM vehicul as v, GROUP BY marca

Which displays the following:

car_type  price 
audi       420  
bmw        1140

But what I want is to display the number * price and the result to be:

car_type  price 
audi       1040  
bmw        4120

Basically.. sum(number*price).. how can I do that? I have tried doing:

SELECT car_type, sum(price*number) FROM vehicul as v, GROUP BY marca

But I am getting:

#1052 - Column 'number' in field list is ambiguous 

Answer 1

select car_type, sum(price*number) as price from vehicul group by car_type..

http://sqlfiddle.com/#!2/3d881/1

you should use sum(field_1*field_2) instead of sum()*sum()

Answer 2

Your query is totally correct. You may have more than 1 table which contain 2 or more number column. Try:

SELECT car_type, sum(price)*sum(number) 
FROM vehicul
GROUP BY marca;

But with the logic you will need this to get total price:

SELECT car_type, sum(price*number) 
FROM vehicul
GROUP BY marca;