I'm trying to migrate an objectcontext/edmx system to dbcontext (EF6) with fluent mapping. I have a few instances like the following. Principal table has a relationship to a dependent table where a non-PK column in the dependent table holds the value of a PK column in the principal. On its own this would be a one to many relationship, but there is a unique index on the dependent table FK columns. Using EDMX mapping, this works fine as long as you define the relationship using mapping rather then referential constraints. Below is an executable example - you don't need the database because it doesn't get that far, currently:
Imports System.Data.Entity
Imports System.Data.Entity.ModelConfiguration
Module Module1
Sub Main()
Using session As New SaturnEntities
Dim res = session.BookingLegSet.Select(Function(x) New With {x.Prefix, x.ID, x.AddressDetails.Address}).ToList
End Using
End Sub
End Module
Partial Public Class BookingLeg
Public Property Prefix As String
Public Property ID As Integer
Public Property LegIndex As Integer
Public Overridable Property AddressDetails As BookingLegAddress
End Class
Partial Public Class BookingLegAddress
Public Property Prefix As String
Public Property ID As Integer
Public Property Address As String
Public Overridable Property BookingLeg As BookingLeg
Property JobLegPrefix As String
Property JobLegID As Integer?
End Class
Public Class BookingLegConfig
Inherits EntityTypeConfiguration(Of BookingLeg)
Public Sub New()
ToTable("JobLegs", "dbo")
HasKey(Function(x) New With {x.Prefix, x.ID})
HasOptional(Function(x) x.AddressDetails).WithRequired(Function(x) x.BookingLeg).Map(Function(x) x.MapKey("Prefix", "ID"))
End Sub
End Class
Public Class BookingLegAddressConfig
Inherits EntityTypeConfiguration(Of BookingLegAddress)
Public Sub New()
ToTable("JobAddresses", "dbo")
HasKey(Function(x) New With {x.Prefix, x.ID})
HasRequired(Function(x) x.BookingLeg).WithOptional(Function(x) x.AddressDetails).Map(Function(x) x.MapKey("JobLegPrefix", "JobLegID"))
End Sub
End Class
Partial Public Class SaturnEntities
Inherits DbContext
Public Sub New()
MyBase.New("data source=dbSaturn;initial catalog=Saturn;integrated security=True;MultipleActiveResultSets=True;")
End Sub
Protected Overrides Sub OnModelCreating(modelBuilder As DbModelBuilder)
modelBuilder.Configurations.Add(New BookingLegConfig)
modelBuilder.Configurations.Add(New BookingLegAddressConfig)
End Sub
Public Overridable Property BookingLegAddressSet() As DbSet(Of BookingLegAddress)
Public Overridable Property BookingLegSet() As DbSet(Of BookingLeg)
End Class
BookingLeg is the principal entity and BookingLegAddress is the dependant. JobLegPrefix and JobLegID in the dependent will be either null or will hold the Prefix and ID values from a BookingLeg record. When you run this you get an error that AddressDetails has been configured with conflicting mapping information. I've tried numerous different ways to map this, but haven't got anywhere - can anyone tell me what I need to do?
Remove the
HasOptional(Function(x) x.AddressDetails).WithRequired(Function(x) x.BookingLeg).Map(Function(x) x.MapKey("Prefix", "ID"))
line from BookingLegConfig
class. Every single relationships must be configured only once in a single place (part of the configuration of any of the two involved entities, but not in both). In this particular case you should keep the second configuration inside BookingLegAddressConfig
class
HasRequired(Function(x) x.BookingLeg).WithOptional(Function(x) x.AddressDetails).Map(Function(x) x.MapKey("JobLegPrefix", "JobLegID"))
because it specifies the correct FK column names.
Also EF6 does not support explicit FK columns for this type of relationship - no HasForeignKey
fluent API, and MapKey
is for specifying shadow property (and column) names. So additionally remove the JobLegPrefix
and JobLegID
properties from the BookingLegAddress
class:
Partial Public Class BookingLegAddress
Public Property Prefix As String
Public Property ID As Integer
Public Property Address As String
Public Overridable Property BookingLeg As BookingLeg
End Class