使用多个条件过滤子对象

Question

I'm having an issue filtering records returned using linq. The objects involved look like this:

Appointment

public partial class Appointment
{
    public Appointment()
    {
        Callbacks = new HashSet<Callback>();
    }

    [Key()]
    public int AppointmentId { get; set; }
    public DateTime Start { get; set; }
    public DateTime? Deleted { get; set;}

    public virtual ICollection<Callback> Callbacks { get; set; }
}

Callback

public partial class Callback
{
    [Key()]
    public int CallbackId { get; set; }
    public DateTime? Deleted { get; set; }
    public virtual Appointment Appointment { get; set; }

    public virtual User AssignedTo { get; set; }
}

User

public partial class User
{
    public User()
    {
        Callbacks = new HashSet<Callback>();
    }

    [Key()]
    public int UserId { get; set; }
    public string LastName { get; set; }
    public string FirstName { get; set; }
    public string Ref { get; set; }

    public virtual ICollection<Callback> Callbacks { get; set; }
}

I'm trying to return records that meet the following criteria:

• The appointment start date must equal searchDate
• The appointment is not deleted
• The appointment start date must not clash with any appointments that the user already has

I've tried using the following query, but no results are returned (there are appointments available for the date 01/03/2016 ( dd/mm/yyyy ).

public List<AppointmentSearchResultsViewModel> SearchByDate(DateTime searchDate, string userName)
{
    return _context.Appointments
        .Where(a =>
            a.Start.Date == searchDate
            && a.Deleted == null
            && a.Callbacks.Any(c =>
                !(c.Appointment.Start != a.Start
                && c.AssignedTo.Ref == userName
                && c.Deleted == null)
        ))
        .OrderBy(a => a.Start)
        .Select(a)
        .ToList();
}

Could anyone help me with how to filter correctly based on the criteria above?

Edit

To try and clarify the model:

• A user has callbacks
  • A callback has an appointment

The aim of this query is to search for all appointments on the searchDate where the user does not already have a callback scheduled for the appointment time.

Answer 1

I think you need a negative comparison for your Any -statement:

!a.Callbacks.Any(c =>
    (c.Appointment.Start == a.Start
    && c.AssignedTo.Ref == userName
    && c.Deleted == null)

Thus you only got those Callbacks from a.Callbacks which have a different Start -date.

Furtheremore you can ommit the Select(a) -statement at the end and immediately call ToList .

Answer 2

The model and what you are trying to achieve is not really clear to me, but I will try my chances anyway on the part O could understand:

  return _context.Appointments
      .Where(a =>
          a.Start.Date == searchDate
          && a.Deleted == null
          && !a.Callbacks.Any(c =>
              (c.Appointment.Start == a.Start
              && c.AssignedTo.Ref == userName
              && c.Deleted == null)
      ))
      .OrderBy(a => a.Start)
      .ToList();

Answer 3

Try this and let me know what you get in return...

return context.Users.Where(user => user.Ref = userName)
                    .SelectMany(user => user.Callbacks)
                    .Where(cb => cb.Appointment.Deleted == null)
                    .Where(cb => cb.Appointment.Start == searchDate)
                    .Select(cb => cb.Appointment)
                    .ToList();

This should return any appointments that clash with the searchDate parameter