public bool Borrow(Loan loan)
{
Book book = this.context.Books.Select(x => x).Where(y => y.ISBN == loan.BookISBN).Take(1).FirstOrDefault();
try
{
if (book != null && this.context.Books.Contains(book))
{
book.Copies -= 1;
}
else
{
throw new ArgumentException("Book does not exist!");
}
this.context.Loans.InsertOnSubmit(loan);
loan.User.TakenBooks += 1;
this.context.SubmitChanges();
}
catch (SqlException e)
{
Console.WriteLine(e.Message);
return false;
}
catch (ArgumentException e)
{
Console.WriteLine(e.Message);
return false;
}
return true;
}
public bool Return(Loan loan)
{
History loanHistory = new History
{
UserId = loan.UserId,
BookISBN = loan.BookISBN,
LeantDate = loan.LeantDate,
ReturnDate = loan.ExpectedReturnDate
};
Book returnedBook = this.context.Books.Select(x => x).Where(y => y.ISBN == loan.BookISBN).Take(1).FirstOrDefault();
try
{
if (returnedBook != null)
{
returnedBook.Copies += 1;
}
else
{
throw new ArgumentException("You tried to return a book that is no in the library!");
}
this.context.Histories.InsertOnSubmit(loanHistory);
this.context.Loans.DeleteOnSubmit(loan);
loan.User.TakenBooks -= 1;
this.context.SubmitChanges();
}
catch (SqlException e)
{
Console.WriteLine(e.Message);
return false;
}
catch (ArgumentException e)
{
Console.WriteLine(e.Message);
return false;
}
return true;
}
private void detach_Loans(Loan entity)
{
this.SendPropertyChanging();
entity.User = null;
}
private void attach_Loans(Loan entity)
{
this.SendPropertyChanging();
entity.User = this;
}
partial void DeleteLoan(Loan instance);
partial void UpdateLoan(Loan instance);
partial void InsertLoan(Loan instance);