private Expression TranslateGroupingKey(Expression expression)
        {
            switch (expression)
            {
            case NewExpression newExpression:
                if (newExpression.Arguments.Count == 0)
                {
                    return(newExpression);
                }

                var newArguments = new Expression[newExpression.Arguments.Count];
                for (var i = 0; i < newArguments.Length; i++)
                {
                    newArguments[i] = TranslateGroupingKey(newExpression.Arguments[i]);
                    if (newArguments[i] == null)
                    {
                        return(null);
                    }
                }

                return(newExpression.Update(newArguments));

            case MemberInitExpression memberInitExpression:
                var updatedNewExpression = (NewExpression)TranslateGroupingKey(memberInitExpression.NewExpression);
                if (updatedNewExpression == null)
                {
                    return(null);
                }

                var newBindings = new MemberAssignment[memberInitExpression.Bindings.Count];
                for (var i = 0; i < newBindings.Length; i++)
                {
                    var memberAssignment  = (MemberAssignment)memberInitExpression.Bindings[i];
                    var visitedExpression = TranslateGroupingKey(memberAssignment.Expression);
                    if (visitedExpression == null)
                    {
                        return(null);
                    }

                    newBindings[i] = memberAssignment.Update(visitedExpression);
                }

                return(memberInitExpression.Update(updatedNewExpression, newBindings));

            default:
                var translation = _expressionTranslator.Translate(expression);
                if (translation == null)
                {
                    return(null);
                }

                return(translation.Type == expression.Type
                        ? (Expression)translation
                        : Expression.Convert(translation, expression.Type));
            }
        }
        public override Expression Visit(Expression expression)
        {
            if (expression == null)
            {
                return(null);
            }

            if (!(expression is NewExpression ||
                  expression is MemberInitExpression ||
                  expression is EntityShaperExpression ||
                  expression is IncludeExpression))
            {
                // This skips the group parameter from GroupJoin
                if (expression is ParameterExpression parameter &&
                    parameter.Type.IsGenericType &&
                    parameter.Type.GetGenericTypeDefinition() == typeof(IEnumerable <>))
                {
                    return(parameter);
                }

                if (_clientEval)
                {
                    switch (expression)
                    {
                    case ConstantExpression _:
                        return(expression);

                    case MaterializeCollectionNavigationExpression materializeCollectionNavigationExpression:
                        //return _selectExpression.AddCollectionProjection(
                        //    _queryableMethodTranslatingExpressionVisitor.TranslateSubquery(
                        //    materializeCollectionNavigationExpression.Subquery),
                        //    materializeCollectionNavigationExpression.Navigation, null);
                        throw new NotImplementedException();

                    case MethodCallExpression methodCallExpression:
                    {
                        if (methodCallExpression.Method.IsGenericMethod &&
                            methodCallExpression.Method.DeclaringType == typeof(Enumerable) &&
                            methodCallExpression.Method.Name == nameof(Enumerable.ToList))
                        {
                            //var elementType = methodCallExpression.Method.GetGenericArguments()[0];

                            //var result = _queryableMethodTranslatingExpressionVisitor.TranslateSubquery(methodCallExpression.Arguments[0]);

                            //return _selectExpression.AddCollectionProjection(result, null, elementType);
                            throw new NotImplementedException();
                        }

                        var subquery = _queryableMethodTranslatingExpressionVisitor.TranslateSubquery(methodCallExpression);

                        if (subquery != null)
                        {
                            //if (subquery.ResultType == ResultType.Enumerable)
                            //{
                            //    return _selectExpression.AddCollectionProjection(subquery, null, subquery.ShaperExpression.Type);
                            //}
                            throw new NotImplementedException();
                        }

                        break;
                    }
                    }


                    var translation = _expressionTranslatingExpressionVisitor.Translate(expression);
                    return(translation == null
                        ? base.Visit(expression)
                        : new ProjectionBindingExpression(_queryExpression, _queryExpression.AddToProjection(translation), expression.Type));
                }
                else
                {
                    var translation = _expressionTranslatingExpressionVisitor.Translate(expression);
                    if (translation == null)
                    {
                        return(null);
                    }

                    _projectionMapping[_projectionMembers.Peek()] = translation;

                    return(new ProjectionBindingExpression(_queryExpression, _projectionMembers.Peek(), expression.Type));
                }
            }

            return(base.Visit(expression));
        }
        public override Expression?Visit(Expression?expression)
        {
            if (expression == null)
            {
                return(null);
            }

            if (!(expression is NewExpression ||
                  expression is MemberInitExpression ||
                  expression is EntityShaperExpression ||
                  expression is IncludeExpression))
            {
                // This skips the group parameter from GroupJoin
                if (expression is ParameterExpression parameter &&
                    parameter.Type.IsGenericType &&
                    parameter.Type.GetGenericTypeDefinition() == typeof(IEnumerable <>))
                {
                    return(parameter);
                }

                if (_clientEval)
                {
                    switch (expression)
                    {
                    case ConstantExpression _:
                        return(expression);

                    case MaterializeCollectionNavigationExpression materializeCollectionNavigationExpression:
                        return(AddCollectionProjection(
                                   _queryableMethodTranslatingExpressionVisitor.TranslateSubquery(
                                       materializeCollectionNavigationExpression.Subquery) !,
                                   materializeCollectionNavigationExpression.Navigation,
                                   materializeCollectionNavigationExpression.Navigation.ClrType.GetSequenceType()));

                    case MethodCallExpression methodCallExpression:
                    {
                        if (methodCallExpression.Method.IsGenericMethod &&
                            methodCallExpression.Method.DeclaringType == typeof(Enumerable) &&
                            methodCallExpression.Method.Name == nameof(Enumerable.ToList))
                        {
                            var subqueryTranslation = _queryableMethodTranslatingExpressionVisitor.TranslateSubquery(
                                methodCallExpression.Arguments[0]);

                            if (subqueryTranslation != null)
                            {
                                return(AddCollectionProjection(
                                           subqueryTranslation,
                                           null,
                                           methodCallExpression.Method.GetGenericArguments()[0]));
                            }
                        }
                        else
                        {
                            var subquery = _queryableMethodTranslatingExpressionVisitor.TranslateSubquery(methodCallExpression);
                            if (subquery != null)
                            {
                                if (subquery.ResultCardinality == ResultCardinality.Enumerable)
                                {
                                    return(AddCollectionProjection(subquery, null, subquery.ShaperExpression.Type));
                                }

                                return(new SingleResultShaperExpression(
                                           new ProjectionBindingExpression(
                                               _queryExpression,
                                               _queryExpression.AddSubqueryProjection(subquery, out var innerShaper),
                                               typeof(ValueBuffer)),
                                           innerShaper,
                                           subquery.ShaperExpression.Type));
                            }
                        }

                        break;
                    }
                    }

                    var translation = _expressionTranslatingExpressionVisitor.Translate(expression);
                    return(translation == null
                        ? base.Visit(expression)
                        : new ProjectionBindingExpression(
                               _queryExpression, _queryExpression.AddToProjection(translation), expression.Type.MakeNullable()));
                }
                else
                {
                    var translation = _expressionTranslatingExpressionVisitor.Translate(expression);
                    if (translation == null)
                    {
                        return(QueryCompilationContext.NotTranslatedExpression);
                    }

                    _projectionMapping[_projectionMembers.Peek()] = translation;

                    return(new ProjectionBindingExpression(_queryExpression, _projectionMembers.Peek(), expression.Type.MakeNullable()));
                }
            }

            return(base.Visit(expression));
        }
Exemplo n.º 4
0
 private Expression TranslateExpression(Expression expression)
 {
     return(_expressionTranslator.Translate(expression));
 }