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Entity Framework - Duplicate Existing Classes, Code First?

I'm trying to think of a way to store actual templates of ticket items in my Entity Framework MVC project. The thing is, I've already done a Code First migration process in the past. What I need to do is create logic in my code to allow someone to save time creating a ticket by using pre-loaded data from a template. My current inheritance model uses an abstract class (MasterTicket) which is used as the parent since to me there can be multiple categories (a Google Calendar based task, "Appointment Task" and a purely internal task, "General Task"). Here's my parent abstract class:
[Table("Ticket")]
[ModelBinder(typeof(MasterTicketBinder))]
public abstract class MasterTicket
{
[Key]
public Guid id{ get; set; }
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int ART { get; set; }
public DateTime openTime{ get; set; }
public DateTime? closeTime { get; set; }
private bool active = true;
public bool Active{ get => active; set => active = value; }
public string summary{ get; set; }
public string description{ get; set; }
public DateTime updateTime{ get; set; }
//TODO: Create foreign key relationship to user model
public Guid userUpdateId{ get; set; }
//TODO: Create foreign key relationship for tickets from other systems
public Guid externalAppId{ get; set; }
//TODO: Create foreign key relationship to user model
public Guid userOpenId{ get; set; }
public Guid? userCloseId { get; set; }
public Guid userOwnerId{ get; set; }
private int timesUpdated = 0;
public int TimesUpdated { get => timesUpdated; set => timesUpdated = value; }
public DateTime expectedCompletionTime{ get; set; }
public DateTime actualCompletionTime{ get; set; }
public List<MasterTicketItem> masterTicketItems{ get; set; }
public MasterTicket()
{
}
}
An here's an example of the concrete Google Calendar-based "Appointment Task" child:
[Table("AppointmentTickets")]
public class ApptTaskTicket : MasterTicket
{
public DateTime currentApptTime { get; set; }
public DateTime? endApptTime { get; set; }
public bool allDay { get; set; }
public string customerName { get; set; }
//TODO: Create foreign relationship
public Guid subjectPrsnlId { get; set; }
public string gCalEventId { get; set; }
public string customerPhone { get; set; }
public string customerEmail { get; set; }
public string preferredContactMethod { get; set; }
public List<ApptConfirmItem> apptConfirmItems { get; set; }
}
I know I can easily create a column for the MasterTicket class to indicate that it's a template, but to me I feel it's cleaner to have a separate "Template Table" if you will that will store pre-existing values that can be filled in with a form. In this case, I think I would WANT to create a duplicate class that would store said templates so that there are only several rows. What would be the best way to do this with Code First? Does someone feel I should take a different approach? Maybe DB First is a better way to go?
In case it matters, here's my DBContext for the Tickets:
// Code-Based Configuration and Dependency resolution
[DbConfigurationType(typeof(MySqlEFConfiguration))]
public class TicketDB : DbContext
{
public TicketDB(): base("AffirmativeServiceSystem.Properties.Settings.AffirmTaskManager")
{
}
public DbSet<MasterTicket> tickets { get; set; }
public DbSet<MasterTicketItem> ticketItems { get; set; }
}

Creating ORM-independent POCO classes

My goal is to create the poco classes without knowing which ORM is going to be used.
Now observe the following code...
public class NeuralModel
{
public NeuralModel()
{
Configurations = new HashSet<NeuralModelConfiguration>();
}
public int Id { get; set; }
public string Name { get; set; }
public DateTime? LastTrained { get; set; }
//Navigation properties
public ICollection<NeuralModelConfiguration> Configurations { get; set; }
//NotMapped properties
[NotMapped]
public NeuralModelConfiguration DefaultConfiguration { get { return Configurations.SingleOrDefault(config => config.IsDefault); } }
[NotMapped]
public bool IsTrained { get { return LastTrained.HasValue; } }
}
public class NeuralModelConfiguration
{
public NeuralModelConfiguration()
{
KeyValues = new HashSet<KeyValuePair<string, string>>();
}
public int Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public bool IsDefault { get; set; }
public ICollection<KeyValuePair<string, string>> KeyValues
public int ModelId { get; set; }
//Navigation properties
public NeuralModel Model { get; set; }
}
Now suppose if I were to use Entity Framework Core, I get into the issue of mapping complex types (in my example it would be ICollection<KeyValuePair<string, string>>).
According to my research I came across two possible solutions:
Serialization
Another Entity
Now my question is that is there a third solution that do not require me to change my poco classes but rather do some sort of hidden processing at the dbcontext level?
Should there not be a third solution then out of the 2 available solutions which one would be considered better in terms of performance?

Composite Key and using Multiple Column Attributes in Entity Framework 6

I am trying to create a composite key using two fields when using code first to existing fields in a table in a db;
[Key,Column("driverId", Order=0)]
[JsonProperty(PropertyName="driverid")]
public override int ID { get; set; }
[Key,Column("type", Order=1)]
[JsonProperty(PropertyName="typeid")]
public int Type { get; set; }
Now when I try to run a new migration i get the following error;
The number of properties in the Dependent and Principal Roles in a relationship constraint must be identical.
DriversToVehicle_Driver_Target_DriversToVehicle_Driver_Source: : The number of properties in the Dependent and Principal Roles in a relationship constraint must be identical.
The DriversToVehicle table is as follows;
public partial class DriversToVehicle
{
[Column("id"), Key]
public int ID { get; set; }
[Column("driverid")]
public int DriverID { get; set; }
[ForeignKey("DriverID")]
public Driver Driver { get; set; }
[Column("vehicleid")]
public int VehicleID { get; set; }
[ForeignKey("VehicleID")]
public Vehicle Vehicle { get; set; }
}
Extending this question, originally a single key on the ID, i.e.
[Column("driverId")]
[JsonProperty(PropertyName="driverid")]
public override int ID { get; set; }
Now moving forward, how will this effect the other entities linking to it (by this i mean code first in the classes)? will ef automatically sort this out? or do I now need to have both keys in other entities when linking to this class?
e.g. as before I would have had
public virtual Driver myDriver;
Obviously now instead of linking on the ID alone it needs to be linked with the Type as well.
Thanks in advance.
EDIT FOR ANSWER
Ok, I extracted the Type out to a seperate class. The main issue is now How do i mark the foreign key as also being a composite key?
I have the following classes
public partial class DriverType
{
[Column("Id")]
[JsonProperty(PropertyName = "drivertypeid")]
public override int ID { get; set; }
[JsonProperty(PropertyName = "drivertype")]
public string Name { get; set; }
}
Then in the Driver I have the following (reduced for brevity);
public partial class Driver : AuditableEntity<int>
{
[Key,Column("driverId", Order=0)]
[JsonProperty(PropertyName="driverid")]
public override int ID { get; set; }
[Key,Column("type", Order=1)]
[ForeignKey("DriverType")]
[JsonProperty(PropertyName="drivertypeid")]
public int DriverTypeId { get; set; }
public DriverType DriverType { get; set; }
How do I then add it to the DriverToVehicle class please? So far I have
public partial class DriversToVehicle
{
[Column("id"), Key]
public int ID { get; set; }
[Column("driverid", Order=0), ForeignKey("Driver")]
public int DriverID { get; set; }
public Driver Driver { get; set; }
[Column("type", Order = 1), ForeignKey("Driver")]
public int DriverTypeId { get; set; }
[ForeignKey("DriverTypeId")]
public DriverType DriverType { get; set; }
}
This doesnt look right to me though?

Since your Drivers table's Primary Key is now (DriverId, Type), you can no longer reference your drivers by DriverId alone - you must reference them by both DriverId and Type. Therefore, your DriversToVehicle table needs to look something like this:
public partial class DriversToVehicle
{
[Column("id"), Key]
public int ID { get; set; }
[Column("driverid")]
public int DriverID { get; set; }
[ForeignKey("DriverID")]
public Driver Driver { get; set; }
[Column("DriverType")]
public int DriverType { get; set; }
[ForeignKey("type")]
public int DriverType { get; set; }
[Column("vehicleid")]
public int VehicleID { get; set; }
[ForeignKey("VehicleID")]
public Vehicle Vehicle { get; set; }
}
However, as #hopeless states above, you may not need to model this join table if you correctly model your Driver and Vehicle types correctly.
HTH.

Entity framework creating a non existent column in the query

This has been puzzling me for quite some time but I keep getting an invalid identifier error when my entity framework tries to execute an oracle query. The classes in question are the following:
public class Projectship : ModelTrackingBase
{
[Column("PROJECTID")]
public long ProjectId { get; set; }
[Column("VISITID")]
public long VisitId { get; set; }
public virtual Bpid Bpid { get; set; } //new
public virtual Visit Visit { get; set; }
}
and
public class Bpid : EntityIdBase
{
[Column("BUDPRJID")]
[MaxLength(38)]
public string BPId { get; set; }
[Column("DESCRIPTION")]
[MaxLength(255)]
public string Description { get; set; }
[Column("CSTOBJ")]
[MaxLength(255)]
public string Custobj { get; set; }
[Column("PVID")]
[MaxLength(255)]
public string Pvid { get; set; }
public virtual ICollection<Projectship> Projectships { get; set; }
public IEnumerable<Visit> Visits
{
get { return Projectships.Select(p => p.Visit); }
}
[NotMapped]
public string DisplayName
{
get { return string.Format("{0}: {1}", BPId , Description); }
}
}
Now the EntityIdBase has the following:
public class EntityIdBase : EntityBase
{
[Column("ID")]
public long Id { get; set; }
}
It tries to keep on looking for a column Bpid_Id in the query. Does someone have any idea?

Bpid_id is created by EF because it can't automatically determine the relationship. Try adding the annotation:
[ForeignKey("ID")]
public virtual Bpid Bpid { get; set; } //new

You have specified a navigation property in the Projectship class
public virtual Bpid Bpid { get; set; }
You have not specified a foreign key to go with the navigation property so Entity Framework has chosen one, and it has chosen the name Bpid_Id. And it should be in the database. It should not be "non-existent".
You will probably find it easier to use Entity Framework if you add a foreign key like this:
public int BpidId { get; set; }
References:
Why does Entity Framework Reinsert Existing Objects into My Database?
Making Do with Absent Foreign Keys

ASP.NET MVC 3: why does it think my class is a complex type?

Building my project using Code First EF.
I have a User class that has, as one of its properties, List<FriendGroup> (where a FriendGroup is basically just a collection of Users, kind of like 'Circles' in Google+). FriendGroup is defined in a different file as a POCO and... here's the thing... I never said anywhere that it is a ComplexType.
But when I try to run my application I get the exception,
System.InvalidOperationException: The type 'FriendGroup' has already been configured as an entity type. It cannot be reconfigured as a complex type.
I would be grateful for any insight anyone might be able to offer on why ASP.NET decided my class is a ComplexType. Thanks in advance!
ETA: relevant bits from my model:
namespace Clade.Models
{
public class User
{
[Key]
public int userID { get; private set; }
[Required]
public Profile profile { get; set; }
[Required]
public string userName { get; set; }
...
public List<FriendGroup> friendGroups { get; set; }
...
public List<AchievementEarned> achievementsEarned { get; set; }
}
}
namespace Clade.Models
{
public class FriendGroup
{
[Key]
[HiddenInput(DisplayValue = false)]
public int friendGroupID { get; private set; }
[HiddenInput(DisplayValue = false)]
public int userID { get; set; }
[Required]
public string friendGroupName { get; set; }
public Privacy defaultPrivacy { get; set; }
[Timestamp]
public DateTime dateCreated { get; set; }
public List<User> usersInFG { get; set; }
public void UpdateMe(FriendGroup editedFG)
{
friendGroupName = editedFG.friendGroupName;
defaultPrivacy = editedFG.defaultPrivacy;
usersInFG = editedFG.usersInFG;
}
}
}
There's also EF code, repositories, etc. but none of them know anything about the inner workings of any POCO. The only thing I see here that may be problematic is that User has a List<FriendGroup> and FriendGroup has a List<User>. But nothing has ever existed that annotated FriendGroup as a ComplexType.
ETA (2): Profile is also just a POCO:
namespace Clade.Models
{
public class Profile
{
[Key]
public int profileID { get; private set; }
public User user { get; set; }
public DiscussionGroup dg { get; set; }
public string location { get; set; }
public Privacy locationPrivacy { get; set; }
public string aboutMe { get; set; }
public Privacy aboutMePrivacy { get; set; }
...
}
}
User does have Lists of a couple of ComplexType-annotated objects, but EF did not complain about those.
namespace Clade.Models
{
[ComplexType]
public class AchievementEarned
{
public Achievement achievement { get; set; }
[Timestamp]
public DateTime dateEarned { get; set; }
}
}
ETA (3): Here's the method in UserRepository where the error occurs. It happens on the line which starts with var results.
public bool Add(User newUser)
{
bool rv = false;
//check to make sure no one else has the same username first
var results = from user in Users
where user.userName.Equals(newUser.userName)
select user;
if (results.Count() == 0)
{
this.context.Users.Add(newUser);
this.Commit();
rv = true;
}
return rv;
}

You may try the following:
Use int property instead of Enum
or try to update to EF 5 beta 2 with
PM> Install-Package EntityFramework -Pre
wich much better supports enums