internal virtual DbExpression OfType(TypeUsage type)
{
// s.OfType<T> is normally translated to s.Filter(e => e is T).Project(e => e as T)
DbExpressionBinding rootBinding = _root.BindAs(_aliasGenerator.Next());
DbExpression filter = this.Filter(rootBinding.Filter(rootBinding.Variable.IsOf(type)));
OrderByLifterBase filterLifter = GetLifter(filter, _aliasGenerator);
DbExpressionBinding filterBinding = filter.BindAs(_aliasGenerator.Next());
DbExpression project = filterLifter.Project(filterBinding.Project(filterBinding.Variable.TreatAs(type)));
return(project);
}
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);
}
/// <summary>
/// Helper method creating the correct filter expression based on the supplied parameters
/// </summary>
private DbFilterExpression BuildFilterExpression(DbExpressionBinding binding, DbExpression predicate, string column)
{
_injectedDynamicFilter = true;
var variableReference = binding.VariableType.Variable(binding.VariableName);
// Create the property based on the variable in order to apply the equality
var tenantProperty = variableReference.Property(column);
// Create the parameter which is an object representation of a sql parameter.
// We have to create a parameter and not perform a direct comparison with Equal function for example
// as this logic is cached per query and called only once
var tenantParameter = tenantProperty.Property.TypeUsage.Parameter(MultitenancyConstants.TenantIdFilterParameterName);
// Apply the equality between property and parameter.
DbExpression newPredicate = tenantProperty.Equal(tenantParameter);
// If an existing predicate exists (normally when called from DbFilterExpression) execute a logical AND to get the result
if (predicate != null)
{
newPredicate = newPredicate.And(predicate);
}
return(binding.Filter(newPredicate));
}
private DbExpression TransformIntersectOrExcept(
DbExpression left,
DbExpression right,
DbExpressionKind expressionKind,
IList <DbPropertyExpression> sortExpressionsOverLeft,
string sortExpressionsBindingVariableName)
{
bool flag1 = expressionKind == DbExpressionKind.Except || expressionKind == DbExpressionKind.Skip;
bool flag2 = expressionKind == DbExpressionKind.Except || expressionKind == DbExpressionKind.Intersect;
DbExpressionBinding input = left.Bind();
DbExpressionBinding expressionBinding = right.Bind();
IList <DbPropertyExpression> propertyExpressionList1 = (IList <DbPropertyExpression>) new List <DbPropertyExpression>();
IList <DbPropertyExpression> propertyExpressionList2 = (IList <DbPropertyExpression>) new List <DbPropertyExpression>();
this.FlattenProperties((DbExpression)input.Variable, propertyExpressionList1);
this.FlattenProperties((DbExpression)expressionBinding.Variable, propertyExpressionList2);
if (expressionKind == DbExpressionKind.Skip && Sql8ExpressionRewriter.RemoveNonSortProperties(propertyExpressionList1, propertyExpressionList2, sortExpressionsOverLeft, input.VariableName, sortExpressionsBindingVariableName))
{
expressionBinding = Sql8ExpressionRewriter.CapWithProject(expressionBinding, propertyExpressionList2);
}
DbExpression dbExpression1 = (DbExpression)null;
for (int index = 0; index < propertyExpressionList1.Count; ++index)
{
DbExpression right1 = (DbExpression)propertyExpressionList1[index].Equal((DbExpression)propertyExpressionList2[index]).Or((DbExpression)propertyExpressionList1[index].IsNull().And((DbExpression)propertyExpressionList2[index].IsNull()));
dbExpression1 = index != 0 ? (DbExpression)dbExpression1.And(right1) : right1;
}
DbExpression dbExpression2 = (DbExpression)expressionBinding.Any(dbExpression1);
DbExpression predicate = !flag1 ? dbExpression2 : (DbExpression)dbExpression2.Not();
DbExpression dbExpression3 = (DbExpression)input.Filter(predicate);
if (flag2)
{
dbExpression3 = (DbExpression)dbExpression3.Distinct();
}
return(dbExpression3);
}
internal DbExpression Filter(DbExpressionBinding input, DbExpression predicate)
{
OrderByLifterBase lifter = GetLifter(input.Expression);
return(lifter.Filter(input.Filter(predicate)));
}
protected DbFilterExpression RebindFilter(DbExpression input, DbFilterExpression filter)
{
DbExpressionBinding inputBinding = input.BindAs(filter.Input.VariableName);
return(inputBinding.Filter(filter.Predicate));
}
/// <summary>
/// This method is used for translating <see cref="DbIntersectExpression"/> and <see cref="DbExceptExpression"/>,
/// and for translating the "Except" part of <see cref="DbSkipExpression"/>.
/// into the follwoing expression:
///
/// A INTERSECT B, A EXCEPT B
///
/// (DISTINCT)
/// |
/// FILTER
/// |
/// | - Input: A
/// | - Predicate:(NOT)
/// |
/// ANY
/// |
/// | - Input: B
/// | - Predicate: (B.b1 = A.a1 or (B.b1 is null and A.a1 is null))
/// AND (B.b2 = A.a2 or (B.b2 is null and A.a2 is null))
/// AND ...
/// AND (B.bn = A.an or (B.bn is null and A.an is null)))
///
/// Here, A corresponds to right and B to left.
/// (NOT) is present when transforming Except
/// for the purpose of translating <see cref="DbExceptExpression"/> or <see cref="DbSkipExpression"/>.
/// (DISTINCT) is present when transforming for the purpose of translating
/// <see cref="DbExceptExpression"/> or <see cref="DbIntersectExpression"/>.
///
/// For <see cref="DbSkipExpression"/>, the input to ANY is caped with project which projects out only
/// the columns represented in the sortExpressionsOverLeft list and only these are used in the predicate.
/// This is because we want to support skip over input with non-equal comarable columns and we have no way to recognize these.
/// </summary>
/// <param name="left"></param>
/// <param name="right"></param>
/// <param name="expressionKind"></param>
/// <param name="sortExpressionsOverLeft">note that this list gets destroyed by this method</param>
/// <param name="sortExpressionsBindingVariableName"></param>
/// <returns></returns>
private DbExpression TransformIntersectOrExcept(DbExpression left, DbExpression right, DbExpressionKind expressionKind, IList <DbPropertyExpression> sortExpressionsOverLeft, string sortExpressionsBindingVariableName)
{
bool negate = (expressionKind == DbExpressionKind.Except) || (expressionKind == DbExpressionKind.Skip);
bool distinct = (expressionKind == DbExpressionKind.Except) || (expressionKind == DbExpressionKind.Intersect);
DbExpressionBinding leftInputBinding = left.Bind();
DbExpressionBinding rightInputBinding = right.Bind();
IList <DbPropertyExpression> leftFlattenedProperties = new List <DbPropertyExpression>();
IList <DbPropertyExpression> rightFlattenedProperties = new List <DbPropertyExpression>();
FlattenProperties(leftInputBinding.Variable, leftFlattenedProperties);
FlattenProperties(rightInputBinding.Variable, rightFlattenedProperties);
//For Skip, we need to ignore any columns that are not in the original sort list. We can recognize these by comparing the left flattened properties and
// the properties in the list sortExpressionsOverLeft
// If any such columns exist, we need to add an additional project, to keep the rest of the columns from being projected, as if any among these
// are non equal comparable, SQL Server 2000 throws.
if (expressionKind == DbExpressionKind.Skip)
{
if (RemoveNonSortProperties(leftFlattenedProperties, rightFlattenedProperties, sortExpressionsOverLeft, leftInputBinding.VariableName, sortExpressionsBindingVariableName))
{
rightInputBinding = CapWithProject(rightInputBinding, rightFlattenedProperties);
}
}
Debug.Assert(leftFlattenedProperties.Count == rightFlattenedProperties.Count, "The left and the right input to INTERSECT or EXCEPT have a different number of properties");
Debug.Assert(leftFlattenedProperties.Count != 0, "The inputs to INTERSECT or EXCEPT have no properties");
//Build the predicate for the quantifier:
// (B.b1 = A.a1 or (B.b1 is null and A.a1 is null))
// AND (B.b2 = A.a2 or (B.b2 is null and A.a2 is null))
// AND ...
// AND (B.bn = A.an or (B.bn is null and A.an is null)))
DbExpression existsPredicate = null;
for (int i = 0; i < leftFlattenedProperties.Count; i++)
{
//A.ai == B.bi
DbExpression equalsExpression = leftFlattenedProperties[i].Equal(rightFlattenedProperties[i]);
//A.ai is null AND B.bi is null
DbExpression leftIsNullExpression = leftFlattenedProperties[i].IsNull();
DbExpression rightIsNullExpression = rightFlattenedProperties[i].IsNull();
DbExpression bothNullExpression = leftIsNullExpression.And(rightIsNullExpression);
DbExpression orExpression = equalsExpression.Or(bothNullExpression);
if (i == 0)
{
existsPredicate = orExpression;
}
else
{
existsPredicate = existsPredicate.And(orExpression);
}
}
//Build the quantifier
DbExpression quantifierExpression = rightInputBinding.Any(existsPredicate);
DbExpression filterPredicate;
//Negate if needed
if (negate)
{
filterPredicate = quantifierExpression.Not();
}
else
{
filterPredicate = quantifierExpression;
}
//Build the filter
DbExpression result = leftInputBinding.Filter(filterPredicate);
//Apply distinct in needed
if (distinct)
{
result = result.Distinct();
}
return(result);
}
