I need random algorithm that fulfills condition

Let's say I have a Product table in the database that have the following properties of id and price:

Product
=======
ProductId int PRIMARY KEY
Price int

For simplicity reasons, I will put Price as int datatype. So right now I would like to use a random algorithm that will retrieve n number of records from the database whereby the Price will sum up to a fixed amount m.

For example:

• n = 5
• m = 100

So I will retrieve 5 Product records that the Price will add up to 100.

One Possible Result:

ProductId       Price
=====================
   5              10
  109             27
  2081            31
  139             21
  331             11
======================
           Sum:  100

I've tried Brute-force approach but it seems to take ages to get the correct sum of 100. Is there any algorithm to do this?