CODEWITHSUNDEEP
c#linqentity-framework
SventoryMang
SventoryMang

Reputation: 10478

LINQ GroupBy 3 properties?

I've got the following class:

public class ProductInventory : Entity
{
    public virtual Product Product { get; set; }
    public DateTime ExpirationDate { get; set; }
    public Manager Manager { get; set; }
}

and a class used in my ViewModels that looks like so:

 public class ProductInventoryCountModel
{
    public Product Product { get; set; }
    public DateTime ExpirationDate { get; set; }
    public int Count { get; set; }
}

I want to get an output of Dictionary<Manager, List<ProductInventoryCountModel> that basically displays Products by manager and then by expiration date so that I can print out actual data looking something like this:

ManagerBoB

 --ProductA, Expires 8/15/13, Count: 10
 --ProductA, Expires 10/10/13, Count: 40
 --ProductB, Expires 6/13/13, Count: 30

ManagerTim

 --ProductA, Expires 10/10/13, Count: 5
 --ProductB, Expires 5/25/13, Count: 10
 --ProductB, Expires 6/13/13, Count 40

how would I write this query in LINQ when starting with a list of ProductInventory? I tried using multiple .GroupBy but that didn't work.

Upvotes: 0

Views: 148

Answers (2)

p.s.w.g
p.s.w.g

Reputation: 149050

You stated that you want a Dictionary<Manager, List<ProductInventoryCountModel>>, so I think you'd have to do something like this:

var dictionary = 
    db.ProductInventory.GroupBy(x => new { x.Manager, x.Product, x.ExpirationDate })
      .ToDictionary(g => g.Key.Manager,
                    g => g.Select(x => new ProductInventoryCountModel 
                                  {
                                      Product = x.Key.Product,
                                      ExpirationDate = x.Key.ExpirationDate,
                                      Count = x.Count()
                                  }).ToList());

Upvotes: 1

SLaks
SLaks

Reputation: 887857

You need to group by an object with multiple properties:

list.GroupBy(p => new { p.Manager, p.Product.Name, p.ExpirationDate.Date })

This works because anonymous types implement Equals() and GetHashCode() to compare by value.

Upvotes: 5

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