PHP根据数组计算几列的总和

I want to sum some columns together based on a array. Previous I did it like this:

$data = $db->query("SELECT idnummer, productnaam,($kolommen[0]+$kolommen[1]+$kolommen[2]+$kolommen[3]+$kolommen[4]+$kolommen[5]+$kolommen[6]+$k
olommen[7]+$kolommen[8]+$kolommen[9]+$kolommen[10]+$kolommen[11]+$kolommen[12]+$kolommen[13]+$
kolommen[14]) AS total FROM wasmachine ORDER BY total DESC, prijs LIMIT 0, 5") or 
trigger_error("Fout in de query");

But I think this is not the right way to do it, because I want it dynamically. I want to use the full array like

$data = $db->query("SELECT idnummer, productnaam,($kolommen) AS total FROM wasmachine ORDER BY total DESC, prijs LIMIT 0, 5") or 
trigger_error("Fout in de query");

This is my database example:

idnummer | productnaam | v1a2 | v2a1 | v3a2
1        |  test 1     |   1  |   2  |   1
2        |  test 2     |   1  |   2  |   1
3        |  test 3     |   1  |   2  |   1
4        |  test 4     |   1  |   2  |   1

I tried it with array_sum and count but I can't figure it out.

Thanks for helping me!

As I understand, your $kolommen array contains names of all rows you need to sum? Then you can write your query this way:

"SELECT idnummer, productnaam,(".join('+', $kolommen).") AS total FROM wasmachine ORDER BY total DESC, prijs LIMIT 0, 5"

Function join will glue elements of the array with string '+'.

Your can use implode as alias function of join, if you wish.