/// <summary>
/// cancels a rental ( > delete from db)
/// </summary>
/// <param name="rentalId">id of rental to cancel</param>
/// <returns>true if successful, otherwise false</returns>
public bool CancelRental(Guid rentalId)
{
using (DbContext = new LudothekEntities()) {
using (var transaction = DbContext.Database.BeginTransaction()) {
try {
Ausleihe rental = DbContext.Ausleihe.FirstOrDefault(r => r.AusleiheKeyGUID == rentalId);
if (rental != null)
{
rental.Spiel.IsAvailable = true;
DbContext.Entry(rental.Spiel).State = EntityState.Modified;
DbContext.Ausleihe.Remove(rental);
DbContext.SaveChanges();
transaction.Commit();
return(true);
}
} catch (Exception e) {
transaction.Rollback();
return(false);
}
}
}
return(false);
}
/// <summary>
/// update an existing entity
/// </summary>
/// <param name="id">entity id to update</param>
/// <param name="newEntity">entity with new values</param>
/// <returns>number of affected rows.</returns>
public int Update(LudothekEntities context, Guid id, TEntity newEntity)
{
context.Entry(newEntity).State = EntityState.Modified;
var numberOfAffectedRows = context.SaveChanges();
return(numberOfAffectedRows);
}
/// <summary>
/// creates a new rental obect
/// </summary>
/// <param name="customerId">id of customer who rents</param>
/// <param name="gameId">id of the game to rent</param>
/// <returns>true if successful, otherwise false</returns>
public bool AddRental(Guid customerId, Guid gameId)
{
using (DbContext = new LudothekEntities())
{
using (var transaction = DbContext.Database.BeginTransaction())
{
try
{
Spiel game = DbContext.Spiel.FirstOrDefault(g => g.SpielKeyGUID == gameId);
Kunde customer = DbContext.Kunde.FirstOrDefault(c => c.KundenKeyGUID == customerId);
if (game == null || !game.IsAvailable)
{
transaction.Dispose();
return(false);
}
Ausleihe rental = new Ausleihe
{
AusleiheKeyGUID = Guid.NewGuid(),
Startdatum = DateTime.Now,
Enddatum = DateTime.Now.AddDays(7),
Kunde = customer,
Spiel = game
};
game.IsAvailable = false;
DbContext.Entry(game).State = EntityState.Modified;
DbContext.Ausleihe.Add(rental);
DbContext.SaveChanges();
transaction.Commit();
return(true);
}
catch (Exception e)
{
transaction.Rollback();
return(false);
}
}
}
}
