internal virtual CollectionColumnMap CreateColumnMapFromReaderAndClrType(
DbDataReader reader, Type type, MetadataWorkspace workspace)
{
DebugCheck.NotNull(reader);
DebugCheck.NotNull(type);
DebugCheck.NotNull(workspace);
// we require a default constructor
var constructor = type.GetDeclaredConstructor();
if (type.IsAbstract() ||
(null == constructor && !type.IsValueType()))
{
throw new InvalidOperationException(Strings.ObjectContext_InvalidTypeForStoreQuery(type));
}
// build a LINQ expression used by result assembly to create results
var memberInfo = new List <Tuple <MemberAssignment, int, EdmProperty> >();
foreach (var prop in type.GetInstanceProperties()
.Select(p => p.GetPropertyInfoForSet()))
{
// for enums unwrap the type if nullable
var propertyUnderlyingType = Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType;
var propType = propertyUnderlyingType.IsEnum() ? propertyUnderlyingType.GetEnumUnderlyingType() : prop.PropertyType;
EdmType modelType;
int ordinal;
if (TryGetColumnOrdinalFromReader(reader, prop.Name, out ordinal) &&
workspace.TryDetermineCSpaceModelType(propType, out modelType) &&
(Helper.IsScalarType(modelType)) &&
prop.CanWriteExtended() &&
prop.GetIndexParameters().Length == 0 &&
null != prop.Setter())
{
memberInfo.Add(
Tuple.Create(
Expression.Bind(prop, Expression.Parameter(prop.PropertyType, "placeholder")),
ordinal,
new EdmProperty(prop.Name, TypeUsage.Create(modelType))));
}
}
// initialize members in the order in which they appear in the reader
var members = new MemberInfo[memberInfo.Count];
var memberBindings = new MemberBinding[memberInfo.Count];
var propertyMaps = new ColumnMap[memberInfo.Count];
var modelProperties = new EdmProperty[memberInfo.Count];
var i = 0;
foreach (var memberGroup in memberInfo.GroupBy(tuple => tuple.Item2).OrderBy(tuple => tuple.Key))
{
// make sure that a single column isn't contributing to multiple properties
if (memberGroup.Count() != 1)
{
throw new InvalidOperationException(
Strings.ObjectContext_TwoPropertiesMappedToSameColumn(
reader.GetName(memberGroup.Key),
String.Join(", ", memberGroup.Select(tuple => tuple.Item3.Name).ToArray())));
}
var member = memberGroup.Single();
var assignment = member.Item1;
var ordinal = member.Item2;
var modelProp = member.Item3;
members[i] = assignment.Member;
memberBindings[i] = assignment;
propertyMaps[i] = new ScalarColumnMap(modelProp.TypeUsage, modelProp.Name, 0, ordinal);
modelProperties[i] = modelProp;
i++;
}
var newExpr = null == constructor?Expression.New(type) : Expression.New(constructor);
var init = Expression.MemberInit(newExpr, memberBindings);
var initMetadata = InitializerMetadata.CreateProjectionInitializer(
(EdmItemCollection)workspace.GetItemCollection(DataSpace.CSpace), init);
// column map (a collection of rows with InitializerMetadata markup)
var rowType = new RowType(modelProperties, initMetadata);
var rowMap = new RecordColumnMap(
TypeUsage.Create(rowType),
"DefaultTypeProjection", propertyMaps, null);
CollectionColumnMap collectionMap = new SimpleCollectionColumnMap(
rowType.GetCollectionType().TypeUsage,
rowType.Name, rowMap, null, null);
return(collectionMap);
}
/// <summary>
/// ScalarColumnMap
/// </summary>
internal override ColumnMap Visit(ScalarColumnMap columnMap, VarMap replacementVarMap)
{
return(new ScalarColumnMap(columnMap.Type, columnMap.Name, columnMap.CommandId, columnMap.ColumnPos));
}