I tried to sum a column using the

Dim myValue As Double =myDt.Compute("Sum("total cost"),"Condition")

But I ony end up with the result.

SyntaxError:SytaxError in argument: expecting an argument for singel column with possible "Child"-qualificator.

Anyone knows what I do wrong

I tried the same code with the column quantity and it worked great
bet not with the total cost column.

I am kinda lost.