Customized column in Linq

Two methods:

var books = _myIBookRepository.RetrieveAllBooks();  
var bokexamples = _myIbokexamples Repository.RetrieveAllBookExample();

Two database table:

BookExample

• BokExampleID (primary key)
• BookID (Foreign key)
• OrderDetailID (Foreign key)

Book

• BookID (primary key)
• KategoryID (Foreign key)
• LanguageID (Foreign key)
• Title

BookID is a foreign key in table BookExample from table Book

If orderdetailID is NULL it means that this specfik bookexample is available in the store

Goal:

Display two column that is "Title" and "stock availiable". "stock availiable" is a customized column that don't exist in the database. "stock available" should contain numbers for instance 2 books of title .... is available.

Problem:

Ha开发者_JS百科ving problem to find right source code in Linq in order to display these two column.

// Fullmetalboy

var query = from b in books
            select new
            {
                Title = b.Title,
                StockAvailable = bookexamples.Count(be => 
                        be.BookID == b.BookID && 
                        be.OrderDetailID == null
                    )
            };

If I understand your question right, this should be what you're looking for.

You could use another class that encapsulates your BookExample class in a form that you want, e.g:

public class BookSummary
{
    public int BookID {get; set; }
    public int BookExampleID {get; set; }
    public bool StockAvailable {get; set; }
    public string Title {get; set; }
}


var books = from b in _myIbokexamples Repository.RetrieveAllBookExample().Include("Book") // I'm assuming that's there, lol
            select new BookSummary
            {
                BookID = b.BookID,
                BookExampleID = b.BookExampleID,
                StockAvailable = b.OrderDetailID == null,
                Title = b.Book.Title
            };