private DbExpression GenerateStructuralTypeResultMappingView(
DbExpression storeFunctionInvoke,
out DiscriminatorMap discriminatorMap)
{
discriminatorMap = (DiscriminatorMap)null;
DbExpression dbExpression = storeFunctionInvoke;
DbExpression queryView;
if (this.m_structuralTypeMappings.Count == 1)
{
Tuple <StructuralType, List <ConditionPropertyMapping>, List <PropertyMapping> > structuralTypeMapping = this.m_structuralTypeMappings[0];
StructuralType structuralType = structuralTypeMapping.Item1;
List <ConditionPropertyMapping> conditions = structuralTypeMapping.Item2;
List <PropertyMapping> propertyMappings = structuralTypeMapping.Item3;
if (conditions.Count > 0)
{
dbExpression = (DbExpression)dbExpression.Where((Func <DbExpression, DbExpression>)(row => FunctionImportMappingComposable.GenerateStructuralTypeConditionsPredicate(conditions, row)));
}
DbExpressionBinding input = dbExpression.BindAs("row");
DbExpression structuralTypeMappingView = FunctionImportMappingComposable.GenerateStructuralTypeMappingView(structuralType, propertyMappings, (DbExpression)input.Variable);
queryView = (DbExpression)input.Project(structuralTypeMappingView);
}
else
{
DbExpressionBinding binding = dbExpression.BindAs("row");
List <DbExpression> list = this.m_structuralTypeMappings.Select <Tuple <StructuralType, List <ConditionPropertyMapping>, List <PropertyMapping> >, DbExpression>((Func <Tuple <StructuralType, List <ConditionPropertyMapping>, List <PropertyMapping> >, DbExpression>)(m => FunctionImportMappingComposable.GenerateStructuralTypeConditionsPredicate(m.Item2, (DbExpression)binding.Variable))).ToList <DbExpression>();
binding = binding.Filter(Helpers.BuildBalancedTreeInPlace <DbExpression>((IList <DbExpression>)list.ToArray(), (Func <DbExpression, DbExpression, DbExpression>)((prev, next) => (DbExpression)prev.Or(next)))).BindAs("row");
List <DbExpression> source = new List <DbExpression>(this.m_structuralTypeMappings.Count);
foreach (Tuple <StructuralType, List <ConditionPropertyMapping>, List <PropertyMapping> > structuralTypeMapping in this.m_structuralTypeMappings)
{
StructuralType structuralType = structuralTypeMapping.Item1;
List <PropertyMapping> propertyMappings = structuralTypeMapping.Item3;
source.Add(FunctionImportMappingComposable.GenerateStructuralTypeMappingView(structuralType, propertyMappings, (DbExpression)binding.Variable));
}
DbExpression projection = (DbExpression)DbExpressionBuilder.Case(list.Take <DbExpression>(this.m_structuralTypeMappings.Count - 1), source.Take <DbExpression>(this.m_structuralTypeMappings.Count - 1), source[this.m_structuralTypeMappings.Count - 1]);
queryView = (DbExpression)binding.Project(projection);
DiscriminatorMap.TryCreateDiscriminatorMap(this.FunctionImport.EntitySet, queryView, out discriminatorMap);
}
return(queryView);
}
private DbExpression GenerateStructuralTypeResultMappingView(
DbExpression storeFunctionInvoke, out DiscriminatorMap discriminatorMap)
{
Debug.Assert(
m_structuralTypeMappings != null && m_structuralTypeMappings.Count > 0,
"m_structuralTypeMappings != null && m_structuralTypeMappings.Count > 0");
discriminatorMap = null;
// Process explicit structural type mappings. The mapping is based on the direct call of the store function
// wrapped into a projection constructing the mapped structural types.
var queryExpression = storeFunctionInvoke;
if (m_structuralTypeMappings.Count == 1)
{
var mapping = m_structuralTypeMappings[0];
var type = mapping.Item1;
var conditions = mapping.Item2;
var propertyMappings = mapping.Item3;
if (conditions.Count > 0)
{
queryExpression = queryExpression.Where((row) => GenerateStructuralTypeConditionsPredicate(conditions, row));
}
var binding = queryExpression.BindAs("row");
var entityTypeMappingView = GenerateStructuralTypeMappingView(type, propertyMappings, binding.Variable);
queryExpression = binding.Project(entityTypeMappingView);
}
else
{
var binding = queryExpression.BindAs("row");
// Make sure type projection is performed over a closed set where each row is guaranteed to produce a known type.
// To do this, filter the store function output using the type conditions.
Debug.Assert(m_structuralTypeMappings.All(m => m.Item2.Count > 0), "In multi-type mapping each type must have conditions.");
var structuralTypePredicates =
m_structuralTypeMappings.Select(m => GenerateStructuralTypeConditionsPredicate(m.Item2, binding.Variable)).ToList();
queryExpression = binding.Filter(
Helpers.BuildBalancedTreeInPlace(
structuralTypePredicates.ToArray(), // clone, otherwise BuildBalancedTreeInPlace will change it
(prev, next) => prev.Or(next)));
binding = queryExpression.BindAs("row");
var structuralTypeMappingViews = new List <DbExpression>(m_structuralTypeMappings.Count);
foreach (var mapping in m_structuralTypeMappings)
{
var type = mapping.Item1;
var propertyMappings = mapping.Item3;
structuralTypeMappingViews.Add(GenerateStructuralTypeMappingView(type, propertyMappings, binding.Variable));
}
Debug.Assert(
structuralTypeMappingViews.Count == structuralTypePredicates.Count,
"structuralTypeMappingViews.Count == structuralTypePredicates.Count");
// Because we are projecting over the closed set, we can convert the last WHEN THEN into ELSE.
DbExpression typeConstructors = DbExpressionBuilder.Case(
structuralTypePredicates.Take(m_structuralTypeMappings.Count - 1),
structuralTypeMappingViews.Take(m_structuralTypeMappings.Count - 1),
structuralTypeMappingViews[m_structuralTypeMappings.Count - 1]);
queryExpression = binding.Project(typeConstructors);
if (DiscriminatorMap.TryCreateDiscriminatorMap(FunctionImport.EntitySet, queryExpression, out discriminatorMap))
{
Debug.Assert(discriminatorMap != null, "discriminatorMap == null after it has been created");
}
}
return(queryExpression);
}