Sum of multiple columns in Child table

[davidhuang]

Hi, I have a Table A and child table B, Column2 is a list of data in Table B. How can I create Column3 to list the sum of columns in Table B? Thanks!

Table A
	Column1
	Column2
	Table B row1 price1, price2, price3
	Table B row2 price1, price2, price3
	Column3
	sum(price1), sum(price2), sum(price3)