internal void ValidateSettingRIConstraints(IEntityWrapper targetEntity, bool settingToNull, bool changingForeignKeyValue)
{
bool isNoTracking = targetEntity != null && targetEntity.MergeOption == MergeOption.NoTracking;
if (settingToNull || // setting the principle to null
changingForeignKeyValue || // existing key does not match incoming key
(targetEntity != null &&
!isNoTracking &&
(targetEntity.ObjectStateEntry == null || // setting to a detached principle
(EntityKey == null && targetEntity.ObjectStateEntry.State == EntityState.Deleted || // setting to a deleted principle
(CachedForeignKey == null && targetEntity.ObjectStateEntry.State == EntityState.Added))))) // setting to an added principle
{
throw EntityUtil.CannotChangeReferentialConstraintProperty();
}
}
/// <summary>
/// This method is called when either the EntityKey or the Value property is set to null when it is
/// already null. For an FK association of a tracked entity the method will attempt to null FKs
/// thereby deleting the relationship. This may result in conceptual nulls being set.
/// </summary>
internal bool AttemptToNullFKsOnRefOrKeySetToNull()
{
if (ReferenceValue.Entity == null &&
WrappedOwner.Entity != null &&
WrappedOwner.Context != null &&
!UsingNoTracking &&
IsForeignKey)
{
// For identifying relationships, we throw, since we cannot set primary key values to null, unless
// the entity is in the Added state.
if (WrappedOwner.ObjectStateEntry.State != EntityState.Added &&
IsDependentEndOfReferentialConstraint(checkIdentifying: true))
{
throw EntityUtil.CannotChangeReferentialConstraintProperty();
}
// For unloaded FK relationships in the context we attempt to null FK values here, which will
// delete the relationship.
RemoveFromLocalCache(EntityWrapperFactory.NullWrapper, resetIsLoaded: true, preserveForeignKey: false);
return(true);
}
return(false);
}