internal abstract TResultType Visit(SimplePolymorphicColumnMap columnMap, TArgType arg);
/// <summary>
/// Creates a column map for a polymorphic type. This method first
/// creates column maps for each type that is a subtype of the input type,
/// and then creates a dictionary of typeid value -> column
/// Finally, a PolymorphicColumnMap is created with these pieces of information
/// </summary>
/// <param name="typeInfo">Info about the type</param>
/// <param name="name">column name</param>
/// <returns></returns>
private SimplePolymorphicColumnMap CreatePolymorphicColumnMap(TypeInfo typeInfo, string name)
{
// if the typeInfo has a DiscriminatorMap, use TrailingSpaceComparer to ensure that lookups
// against discriminator values that SQL Server has right-padded (e.g. nchar and char) are properly
// interpreted
Dictionary<object, TypedColumnMap> discriminatorMap = new Dictionary<object, TypedColumnMap>(
typeInfo.RootType.DiscriminatorMap == null ? null : TrailingSpaceComparer.Instance);
// abstract types may not have discriminator values, but may nonetheless be interesting
List<TypedColumnMap> allMaps = new List<TypedColumnMap>();
// SQLBUDT #433011 -- Polymorphic types must construct column maps
// that map to the entire type hierarchy, so we
// need to use the RootType, not the current type.
TypeInfo rootTypeInfo = typeInfo.RootType;
// Get the type discriminant column first
SimpleColumnMap typeIdColumnMap = CreateTypeIdColumnMap(rootTypeInfo.TypeIdProperty);
// Prepare a place for the constructors to put the columns on the base
// type, as they identify them.
TypedColumnMap rootTypeColumnMap = null;
// process complex/entity types appropriately
// use the same name for the column
if (md.TypeSemantics.IsComplexType(typeInfo.Type))
{
rootTypeColumnMap = CreateComplexTypeColumnMap(rootTypeInfo, name, null, discriminatorMap, allMaps);
}
else
{
rootTypeColumnMap = CreateEntityColumnMap(rootTypeInfo, name, null, discriminatorMap, allMaps, true);
}
// Naturally, nothing is simple; we need to walk the rootTypeColumnMap hierarchy
// and find the column map for the type that we are supposed to have as the base
// type of this hierarchy.
TypedColumnMap baseTypeColumnMap = null;
foreach (TypedColumnMap value in allMaps)
{
if (md.TypeSemantics.IsStructurallyEqual(value.Type, typeInfo.Type))
{
baseTypeColumnMap = value;
break;
}
}
PlanCompiler.Assert(null != baseTypeColumnMap, "Didn't find requested type in polymorphic type hierarchy?");
// Create a polymorphic column map
SimplePolymorphicColumnMap result = new SimplePolymorphicColumnMap(typeInfo.Type, name, baseTypeColumnMap.Properties, typeIdColumnMap, discriminatorMap);
return result;
}
public void TranslateColumnMap_returns_correct_columntypes_and_nullablecolumns_for_discriminated_types()
{
var metadataWorkspaceMock = new Mock<MetadataWorkspace>();
metadataWorkspaceMock.Setup(m => m.GetQueryCacheManager()).Returns(QueryCacheManager.Create());
var typeChoices = new Dictionary<object, TypedColumnMap>();
var entityColumnMap = (EntityColumnMap)BuildSimpleEntitySetColumnMap(metadataWorkspaceMock).Element;
typeChoices.Add(true, entityColumnMap);
var recordMap = new SimplePolymorphicColumnMap(
entityColumnMap.Type, "E", new ColumnMap[0],
new ScalarColumnMap(TypeUsage.Create(PrimitiveType.GetEdmPrimitiveType(PrimitiveTypeKind.Boolean)), "discriminator", 0, 2),
typeChoices);
var collectionMap = new SimpleCollectionColumnMap(
entityColumnMap.Type, "MockCollectionType", recordMap, null, null);
var factory =
new Translator().TranslateColumnMap<object>(
collectionMap, metadataWorkspaceMock.Object, new SpanIndex(), MergeOption.NoTracking, streaming: false, valueLayer: false);
Assert.NotNull(factory);
Assert.Equal(new[] { typeof(int), typeof(int), typeof(bool) }, factory.ColumnTypes);
Assert.Equal(new[] { true, true, true }, factory.NullableColumns);
}
