Пример #1
0
        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 ParameterExpression parameterExpression:
                        return(Expression.Call(
                                   _getParameterValueMethodInfo.MakeGenericMethod(parameterExpression.Type),
                                   QueryCompilationContext.QueryContextParameter,
                                   Expression.Constant(parameterExpression.Name)));

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

                    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));
                        }

                        var subquery = _queryableMethodTranslatingExpressionVisitor.TranslateSubquery(methodCallExpression);

                        if (subquery != null)
                        {
                            if (subquery.ResultCardinality == ResultCardinality.Enumerable)
                            {
                                return(_selectExpression.AddCollectionProjection(subquery, null, subquery.ShaperExpression.Type));
                            }