SQL to IQueryable LINQ

Question

Hello I am trying to convert the following SQL statement into its LINQ equivalent and since I am really new to .net (coding for one day) i have gotten stuck on this for hours now.

SELECT * 
 FROM Books 
 WHERE BookID IN (SELECT BookID 
              FROM Borrows 
              WHERE UserID = 2) 

This is the model

public class LibUser
{       
    [Key]
    public int UserID { get; set; }
    [Required, StringLength(50), Display(Name = "First Name")]
    public string UserFirstName { get; set; }
    [Required, StringLength(50), Display(Name = "Last Name")]
    public string UserLastName { get; set; }
    [Required, StringLength(10000), Display(Name = "Residence"), DataType(DataType.MultilineText)]
    public string Adress { get; set; }
}

public class Book { 
    [Key]
    public int BookID { get; set; }
    public string Title { get; set; }
    public string Author { get; set; }
    public DateTime Published{ get; set; }
}

public class Borrowed {
    [Key]
    public int BorrowID { get; set; }
    public int UserID { get; set; }
    public int BookID { get; set; } 
}

I would greatly appreciate anyones help.

EDIT

Context class

public class LibraryContext : DbContext
{

          public LibraryContext()
        : base("libromatic")
    {
    }

    public DbSet<LibUser> LibUsers { get; set; }
    public DbSet<Book> Books { get; set; }
    public DbSet<Borrowed> Borrows { get; set; }

}

Answer 1

Assuming your context is called db, you could do the following query

var borrowedBooksForUser = db.Books
     .Where(b => db.Borrowed.Any(x => x.UserID == 2 && x.BookID == b.BookID));

Answer 2

It might be preferable to do this with a join.

The argument is: If a user borrows huge amounts of books, or there is an error in the data, then your subquery could return a lot of IDs, and SQL 'IN' clauses on long lists can get really slow.

Using a join:

SQL query:

SELECT Books.* FROM Books 
  JOIN Borrows ON Borrows.BookID = Books.BookID
  WHERE Borrows.UserID = 2 

Linq statement:

var allBooksBorrowedByUser2 = db.Borrowed
                .Where(borrow => borrow.UserID == 2)
                .Join(db.Books,
                      borrow => borrow.BookID,
                      book => book.BookID,
                      (borrow, book) => book);