internal static IEnumerable <string> GetDependentPropertyNames(NavigationProperty navigationProperty, bool checkRelationshipType)
{
if (checkRelationshipType)
{
if (navigationProperty.ToEndMember.RelationshipMultiplicity == RelationshipMultiplicity.ZeroOrOne &&
navigationProperty.FromEndMember.RelationshipMultiplicity == RelationshipMultiplicity.One)
{
// Get constraint when this association is on the "parent" (aka "from") side. This means
// that the navProperty represents a Children association in a 1-1 relationship. For example,
// this could be a Item-ItemDetail scenario where the ItemDetail table has a PK that is also an FK
// into the Item table (thus ensuring the 1-1 cardinality). We need to special case this situation because normally we would try
// to build a foreign key name of the form "Item.ItemID", but we want just "ItemID".
AssociationType relationshipType = (AssociationType)navigationProperty.RelationshipType;
ReferentialConstraint constraint = relationshipType.ReferentialConstraints.FirstOrDefault(c => c.ToRole == navigationProperty.ToEndMember);
if (constraint != null)
{
return(constraint.FromProperties.Select(p => p.Name));
}
// Fall back on the primary keys if no constraints were found but only if we are on the parent side. i.e the 1 side Item side in an Item-ItemDetail
// Get the primary keys on the "from" side of the relationship. i.e Product.Category -> ProductID
return(navigationProperty.FromEndMember.GetEntityType().KeyMembers.Select(m => m.Name));
}
}
return(navigationProperty.GetDependentProperties().Select(m => m.Name));
}
private static IPropertyConstraint GetForeignKeyConstraint(NavigationProperty navProp)
{
if (navProp.GetDependentProperties().Count() != 1 ||
navProp.ToEndMember.GetEntityType().KeyProperties.Count != 1)
{
return(null);
}
var dependencyProp = navProp.GetDependentProperties().Single();
var keyProp = navProp.ToEndMember.GetEntityType().KeyProperties.Single();
var fromType = navProp.FromEndMember.GetEntityType().GetClrType();
var toType = navProp.ToEndMember.GetEntityType().GetClrType();
var navPropInfo = navProp.GetProperty();
var foreignKeyPropInfo = fromType.GetProperty(dependencyProp);
var keyPropInfo = toType.GetProperty(keyProp);
var keyType = keyPropInfo.PropertyType;
var type = typeof(ForeignKeyConstraint <, ,>)
.MakeGenericType(fromType, toType, keyType);
return((IPropertyConstraint)Activator.CreateInstance(type, navPropInfo, foreignKeyPropInfo, keyPropInfo));
}