private Expression LiftSubQuery(
IQuerySource querySource, Expression itemsExpression, Expression expression)
{
var subQueryExpression = itemsExpression as SubQueryExpression;
if (subQueryExpression == null)
{
return(expression);
}
var subQueryModelVisitor
= (RelationalQueryModelVisitor)QueryCompilationContext
.CreateQueryModelVisitor(this);
subQueryModelVisitor.VisitSubQueryModel(subQueryExpression.QueryModel);
if ((subQueryModelVisitor.Queries.Count == 1) &&
!subQueryModelVisitor.RequiresClientEval &&
!subQueryModelVisitor.RequiresClientSelectMany &&
!subQueryModelVisitor.RequiresClientJoin &&
!subQueryModelVisitor.RequiresClientFilter &&
!subQueryModelVisitor.RequiresClientProjection &&
!subQueryModelVisitor.RequiresClientOrderBy &&
!subQueryModelVisitor.RequiresClientResultOperator)
{
var subSelectExpression = subQueryModelVisitor.Queries.First();
if ((!subSelectExpression.OrderBy.Any() ||
(subSelectExpression.Limit != null)) &&
(QueryCompilationContext.IsLateralJoinSupported || !subSelectExpression.IsCorrelated() || !(querySource is AdditionalFromClause)))
{
subSelectExpression.PushDownSubquery().QuerySource = querySource;
AddQuery(querySource, subSelectExpression);
var liftSubQuery
= new QuerySourceUpdater(
querySource,
QueryCompilationContext,
LinqOperatorProvider,
subSelectExpression)
.Visit(subQueryModelVisitor.Expression);
return
(liftSubQuery);
}
}
return(expression);
}
protected override Expression VisitSubQueryExpression(SubQueryExpression expression)
{
var queryModelVisitor = QueryCompilationContext.CreateQueryModelVisitor();
queryModelVisitor.VisitQueryModel(expression.QueryModel);
var subExpression = queryModelVisitor.Expression;
if (queryModelVisitor._streamedSequenceInfo == null)
{
return(subExpression);
}
if (typeof(IQueryable).GetTypeInfo().IsAssignableFrom(expression.Type.GetTypeInfo()))
{
subExpression
= Expression.Call(
_asQueryableShim.MakeGenericMethod(
queryModelVisitor._streamedSequenceInfo.ResultItemType),
subExpression);
}
return(Expression.Convert(subExpression, expression.Type));
}
private Expression LiftSubQuery(
IQuerySource querySource, Expression itemsExpression, QueryModel queryModel, Expression expression)
{
var subQueryExpression = itemsExpression as SubQueryExpression;
if (subQueryExpression == null)
{
return(expression);
}
var subQueryModelVisitor
= (RelationalQueryModelVisitor)QueryCompilationContext.CreateQueryModelVisitor(this);
subQueryModelVisitor.VisitSubQueryModel(subQueryExpression.QueryModel);
SelectExpression subSelectExpression = null;
if (subQueryModelVisitor.Queries.Count == 1 &&
!subQueryModelVisitor.RequiresClientFilter &&
!subQueryModelVisitor.RequiresClientSelectMany &&
!subQueryModelVisitor.RequiresClientProjection &&
!subQueryModelVisitor.RequiresClientResultOperator)
{
subSelectExpression = subQueryModelVisitor.Queries.First();
}
if (subSelectExpression != null &&
(!subSelectExpression.OrderBy.Any() ||
subSelectExpression.Limit != null) &&
(QueryCompilationContext.IsCrossApplySupported ||
(!subSelectExpression.IsCorrelated() ||
!(querySource is AdditionalFromClause))))
{
subSelectExpression.PushDownSubquery().QuerySource = querySource;
AddQuery(querySource, subSelectExpression);
var shapedQueryMethodExpression
= new ShapedQueryFindingExpressionVisitor(QueryCompilationContext)
.Find(subQueryModelVisitor.Expression);
var shaperLambda = (LambdaExpression)shapedQueryMethodExpression.Arguments[2];
var shaperMethodCall = (MethodCallExpression)shaperLambda.Body;
var shaperMethod = shaperMethodCall.Method;
var shaperMethodArgs = shaperMethodCall.Arguments.ToList();
if (!QueryCompilationContext.QuerySourceRequiresMaterialization(querySource) &&
shaperMethod.MethodIsClosedFormOf(RelationalEntityQueryableExpressionVisitor.CreateEntityMethodInfo))
{
shaperMethod = RelationalEntityQueryableExpressionVisitor.CreateValueBufferMethodInfo;
shaperMethodArgs.RemoveRange(5, 5);
}
else
{
subSelectExpression.ExplodeStarProjection();
}
var innerQuerySource = (IQuerySource)((ConstantExpression)shaperMethodArgs[0]).Value;
foreach (var queryAnnotation
in QueryCompilationContext.QueryAnnotations
.Where(qa => qa.QuerySource == innerQuerySource))
{
queryAnnotation.QuerySource = querySource;
}
shaperMethodArgs[0] = Expression.Constant(querySource);
var querySourceReferenceExpression
= queryModel.SelectClause.Selector as QuerySourceReferenceExpression;
if (querySourceReferenceExpression != null &&
querySourceReferenceExpression.ReferencedQuerySource == querySource)
{
if (subQueryExpression.QueryModel != null)
{
queryModel.SelectClause.Selector = subQueryExpression.QueryModel.SelectClause.Selector;
QueryCompilationContext.QuerySourceMapping
.ReplaceMapping(
subQueryExpression.QueryModel.MainFromClause,
QueryResultScope.GetResult(
QueryResultScopeParameter,
querySource,
shaperMethod.ReturnType.GenericTypeArguments[0]));
}
}
return(Expression.Call(
QueryCompilationContext.QueryMethodProvider.ShapedQueryMethod
.MakeGenericMethod(shaperMethod.ReturnType),
shapedQueryMethodExpression.Arguments[0],
shapedQueryMethodExpression.Arguments[1],
Expression.Lambda(
Expression.Call(shaperMethod, shaperMethodArgs),
shaperLambda.Parameters[0])));
}
return(expression);
}