If I have a value from a column which repeats itself more than once and I want to use the value only once how can i do it ?
example
Suppose someone buys our product in qty of 25 & they pay 5 for shipping. So in first delivery we send them 10 pcs, they paid
5 bucks for shipping, at a later time we send them remaining 15 pcs but shipping was charged to them at once.. my problem is since there are 2 or more rows for split qty for every row it shows 5 bucks charge so when I am creating a summary.. Instead of getting $5 for the entire invoice I get 10 which is 5 * 2=10
select contract,invoiceid, prod id,maker,model,price,qty,shipping from product
100000, 122, 100,Jam, oil, 100, 10,5
100000,122,100,Jam,Oil,100,15 ,5
Whats the correct approach to resolve this ????
someone pplease