/// <summary>Visits a select clause.</summary>
/// <param name="selectClause">Select clause to be visited.</param>
/// <param name="queryModel">Query model containing given select clause.</param>
public override void VisitSelectClause(SelectClause selectClause, Remotion.Linq.QueryModel queryModel)
{
queryModel.MainFromClause.Accept(this, queryModel);
QuerySourceReferenceExpression querySource = FindQuerySource(selectClause.Selector);
_visitor.Visit(selectClause.Selector);
QueryComponent component = _visitor.RetrieveComponent();
_query = _visitor.Query;
_mainFromComponent = _query.FindAllComponents <StrongEntityAccessor>().Where(item => item.SourceExpression == querySource.ReferencedQuerySource).First();
if (_query.Subject == null)
{
_query.Subject = _mainFromComponent.About;
UnboundConstrain genericConstrain = new UnboundConstrain(new Identifier("s"), new Identifier("p"), new Identifier("o"), _mainFromComponent.SourceExpression.FromExpression);
_mainFromComponent.Elements.Insert(0, genericConstrain);
_mainFromComponent.UnboundGraphName = null;
_query.Select.Add(genericConstrain);
}
_subject = _query.Subject;
_query.Select.Add(_mainFromComponent);
VisitBodyClauses(queryModel.BodyClauses, queryModel);
VisitResultOperators(queryModel.ResultOperators, queryModel);
OverrideSelector(component, selectClause.Selector);
}
private void ProcessSelectableUnboundConstrain(UnboundConstrain expression, bool isSubQuery, Func <string, string> createVariableName, StrongEntityAccessor mainEntityAccessor)
{
if ((!isSubQuery) && (expression.Subject is Identifier) && (expression.Predicate is Identifier) && (expression.Value is Identifier))
{
_subjectVariableName = ((Identifier)expression.Subject).Name;
_predicateVariableName = ((Identifier)expression.Predicate).Name;
_objectVariableName = ((Identifier)expression.Value).Name;
}
}
private void OverrideLiteralSelector(StrongEntityAccessor entityAccessor)
{
if (_mainFromComponent.Elements[0] is UnboundConstrain)
{
UnboundConstrain unboundConstrain = (UnboundConstrain)_mainFromComponent.Elements[0];
entityAccessor.Elements.Add(new Filter(new BinaryOperator(MethodNames.Equal, unboundConstrain.Subject, _mainFromComponent.About)));
entityAccessor.Elements.Add(new Filter(new BinaryOperator(MethodNames.Equal, unboundConstrain.Predicate, new Literal(_propertyMapping.Uri))));
_query.Select.Add((Identifier)unboundConstrain.Subject);
}
}
/// <summary>Visit an unbound constrain.</summary>
/// <param name="unboundConstrain">Unbound constrain to be visited.</param>
protected override void VisitUnboundConstrain(UnboundConstrain unboundConstrain)
{
_commandText.Append(Indentation);
VisitComponent(unboundConstrain.Subject);
_commandText.Append(" ");
VisitComponent(unboundConstrain.Predicate);
_commandText.Append(" ");
VisitComponent(unboundConstrain.Value);
_commandText.Append(" . ");
_commandText.AppendLine();
}
private void VisitCountResultOperator(CountResultOperator countResultOperator, Remotion.Linq.QueryModel queryModel, int index)
{
Call distinct = new Call(MethodNames.Distinct);
distinct.Arguments.Add(_mainFromComponent.About);
UnboundConstrain constrain = (UnboundConstrain)_mainFromComponent.Elements.FirstOrDefault(item => item.GetType() == typeof(UnboundConstrain));
if (constrain != null)
{
_mainFromComponent.Elements.Remove(constrain);
}
Call count = new Call(MethodNames.Count);
count.Arguments.Add(distinct);
_query.Select.Clear();
Alias alias = new Alias(count, new Identifier(_query.CreateVariableName(_query.RetrieveIdentifier(_mainFromComponent.About.Name) + "Count"), typeof(int)));
_query.Select.Add(alias);
}
private void OverrideEntitySelector(Identifier identifier)
{
StrongEntityAccessor entityAccessor = _query.FindAllComponents <StrongEntityAccessor>().Where(item => item.About == identifier).FirstOrDefault();
if (entityAccessor == null)
{
entityAccessor = new StrongEntityAccessor(identifier);
_query.Elements.Add(entityAccessor);
}
if ((entityAccessor.UnboundGraphName == null) || (entityAccessor.UnboundGraphName == entityAccessor.About))
{
entityAccessor.UnboundGraphName = (from accessor in _query.FindAllComponents <StrongEntityAccessor>()
from constrain in accessor.Elements.OfType <EntityConstrain>()
where (constrain.Value is Identifier) && ((Identifier)constrain.Value == identifier)
select accessor.About).FirstOrDefault() ?? identifier;
UnboundConstrain genericConstrain = new UnboundConstrain()
{
Subject = new Identifier(identifier.Name + "_s"), Predicate = new Identifier(identifier.Name + "_p"), Value = new Identifier(identifier.Name + "_o")
};
entityAccessor.Elements.Add(genericConstrain);
UnboundConstrain targetConstrain = new UnboundConstrain()
{
Subject = identifier, Predicate = new Identifier(identifier.Name + "p"), Value = new Identifier(identifier.Name + "o")
};
entityAccessor.Elements.Add(targetConstrain);
_query.Select.Clear();
if (_mainFromComponent.Elements[0] is UnboundConstrain)
{
ConditionalConstrainSelector selector = new ConditionalConstrainSelector(entityAccessor, genericConstrain, (UnboundConstrain)_mainFromComponent.Elements[0]);
_query.Select.Add(selector);
}
_query.Select.Add(entityAccessor);
}
}
/// <summary>Visit an unbound constrain.</summary> /// <param name="unboundConstrain">Unbound constrain to be visited.</param> protected abstract void VisitUnboundConstrain(UnboundConstrain unboundConstrain);
/// <summary>Default constructor with nagivated unbound constrain.</summary>
/// <param name="unboundConstrain">Nagivated unbound constrain.</param>
internal UnboundConstrainNavigator(UnboundConstrain unboundConstrain)
: base(unboundConstrain)
{
}
/// <summary>Default constructor with nagivated unbound constrain.</summary>
/// <param name="unboundConstrain">Nagivated unbound constrain.</param>
internal UnboundConstrainNavigator(UnboundConstrain unboundConstrain)
: base(unboundConstrain)
{
}
