LINQ query from a list<> inside of a list<>

[kgkgkg]

Hey everyone,

I've dealt with some simple LINQ queries before, but am not sure how to tackle this one...

I've got a project I'm working on where I'm dealing with two classes I've created, 'Package' and 'Product' (along with other classes).

I've also created a Job class which houses a List<Package> and inside the Package class it houses a List<Product>.

(NOTE): a Package is just a grouping of Products. so each Package could have 2 different scenarios: 1)it has all unique Products or 2) it could have some of the same Products that other Packages have and some unique)

//This is just an abstract view of the classes
//    there are other things in each class
 
public class Job
{
    int jobID;
    List<Package> packages;
}
 
public class Package
{
    int packageID;
    List<Product> products;
}
 
public class Product
{
    int productID;
    int quantity;
}
 

So now for my question, as I explained in the above note, some Packages can have the same Product in them. Well I'm looking to write a function in the Job class to pull a LINQ query to return each unique Product class, AND also the sum of the 'quantity' data member in the Product class.

This analogy may help: if a grocery store wanted to take every purchase (package class) from a single day (job class) and wanted to know the total quantity of each product sold and the name of the product.

the ideal query would return:
(ID#1:Qty 4),(ID#2:Qty 1),(ID#3:Qty 2),(ID#12:Qty 3),(ID#13:Qty 1)



If I did a horrible job of explaining or if you need more info, just let me know and I'll find another way of explaining it!

Thank you!

[Bryan Cheung]

You'll have to play with the Distinct() and Sum() methods from List<>.

GL,
Bryan.