Left join in LINQ

Here is a sample of a left join using LINQ

void Main()
{

  List<Book> bookList = new List<Book>
  {
      new Book{BookID=1, BookNm="DevCurry.com Developer Tips"},
      new Book{BookID=2, BookNm=".NET and COM for Newbies"},
      new Book{BookID=3, BookNm="51 jQuery ASP.NET Recipes"},
      new Book{BookID=4, BookNm="Motivational Gurus"},
      new Book{BookID=5, BookNm="Spiritual Gurus"}
  };

  List<Order> bookOrders = new List<Order>{
      new Order{OrderID=1, BookID=1, PaymentMode="Cheque"},
      new Order{OrderID=2, BookID=5, PaymentMode="Credit"},
      new Order{OrderID=3, BookID=1, PaymentMode="Cash"},
      new Order{OrderID=4, BookID=3, PaymentMode="Cheque"},
      new Order{OrderID=5, BookID=5, PaymentMode="Cheque"},
      new Order{OrderID=6, BookID=4, PaymentMode="Cash"}
  };
  
  var orderForBooks = from bk in bookList
            join ordr in bookOrders
            on bk.BookID equals ordr.BookID
            into a
            from b in a.DefaultIfEmpty(new Order())
            select new
            {
                bk.BookID,
                Name = bk.BookNm,
                b.PaymentMode
            };

}

public class Book
{
    public int BookID { get; set; }
    public string BookNm { get; set; }
}

public class Order
{
    public int OrderID { get; set; }
    public int BookID { get; set; }
    public string PaymentMode { get; set; }
}

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~Tim

sample is not gonna help me. I've seen samples. I need my query working.

Hi Camilla;

See if this is what you are looking for.

var consumerList = (from data in _dataContext.Consumers
                    join s in _dataContext.StateProvinces on data.StateId equals s.Id
                    join c in _dataContext.Countries on data.CountryId equals c.Id
                    join p in _dataContext.Promotions on data.PromotionId equals p.Id
                    join t in _dataContext.SubmissionStatus on data.SubmissionStatusId equals t.Id
                    join r in _dataContext.Products on data.ProductId equals r.Id
                    join pp in _dataContext.ProductsInPromotion on  data.ProductId equals pp.ProductId into pInfoGroup
                    orderby data.CreateDate descending
                    select new 
                    {
                        //....
                        // PInfo will be a collection and will be empty collection if no records are in it
                        PInfo = pInfoGroup.DefaultIfEmpty() 
                    };

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I have this in "select new" section. How can I get this working? I want a column called "rebate" from it. If it's too much hassle, I just move this to a stored proc. How do I use that "PInfo" here to get the individual fields?

var consumerList = (from data in _dataContext.Consumers
               join s in _dataContext.StateProvinces on data.StateId equals s.Id
               join c in _dataContext.Countries on data.CountryId equals c.Id
               join p in _dataContext.Promotions on data.PromotionId equals p.Id
               join t in _dataContext.SubmissionStatus on data.SubmissionStatusId equals t.Id
               join r in _dataContext.Products on data.ProductId equals r.Id
               select new
               {
                   data.Id,
                   data.FirstName,
                   data.LastName,
                   data.Address,
                   data.City,
                   data.PostalCode,
                   state = s.Name,
                   stateId = s.Id,
                   country = c.Name,
                   countryId = c.Id,
                   data.EmailAddress,
                   promotion = p.Code,
                   data.PhoneNumber,
                   data.PurchaseDate,
                   data.RetailLocation,
                   data.ProductSerialNumber,
                   status = t.Code,
                   product = r.ProductModel,
                   data.ConfirmationCode,
                   t.Code,
                   data.CreateDate,

                   PromotionId = p.Id,
                   SubmissionStatusId = t.Id,
                   ProductId = r.Id,
                   data.Filename



               }).Where(x => x.Id == id);

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Not understanding your question. Are you saying that from the ProductsInPromotion you want a to return a field called rebate?

I'm saying you have this

 PInfo = pInfoGroup.DefaultIfEmpty() 

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But I have

 select new
               {
                   data.Id,
                   data.FirstName,
                   data.LastName,
                   data.Address,
                   data.City,
                   data.PostalCode,
                   state = s.Name,
                   stateId = s.Id,
                  ...

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How can I keep my code and use what you have? how does your line of code comes into play?

thanks, let me try

Not a problem, glad to help.