i am facing problem with sum payment_value : 
suppose i inserted to payment_value in families payments 200$ to father and mother and 300$ in childrenpayments for each child 100$ .. now i want to query this to sum payment_value for this family .. i want it like this
i want sql query like this :
SELECT
family_id,
father_name,
mother_name,
last_name,
'children count' AS [here count children for each family],
'sumpayment' AS [here i want sum payment for father and mother and children]
FROM dbo.Families