LINQ Generic Join and Entity Framework

My requirement is to implement a Generic Join method which would IQueryable Join .

I have used the Join method as shown below :

public static IQueryable Join(this IQueryable outer, IEnumerable inner, string outerSelector, string innerSelector, string resultsSelector, params object[] values)
    {
        if (inner == null) throw new ArgumentNullException("inner");
        if (outerSelector == null) throw new ArgumentNullException("outerSelector");
        if (innerSelector == null) throw new ArgumentNullException("innerSelector");
        if (resultsSelector == null) throw new ArgumentNullException("resultsSelctor");

        System.Linq.Expressions开发者_运维知识库.LambdaExpression outerSelectorLambda = DynamicExpression.ParseLambda(outer.ElementType, null, outerSelector, values);
        System.Linq.Expressions.LambdaExpression innerSelectorLambda = DynamicExpression.ParseLambda(inner.AsQueryable().ElementType, null, innerSelector, values);

        System.Linq.Expressions.ParameterExpression[] parameters = new System.Linq.Expressions.ParameterExpression[] {
        System.Linq.Expressions.Expression.Parameter(outer.ElementType, "outer"), System.Linq.Expressions.Expression.Parameter(inner.AsQueryable().ElementType, "inner") };
        System.Linq.Expressions.LambdaExpression resultsSelectorLambda = DynamicExpression.ParseLambda(parameters, null, resultsSelector, values);

        return outer.Provider.CreateQuery(
            System.Linq.Expressions.Expression.Call(
                typeof(Queryable), "Join",
                new Type[] 
                { 
                    outer.ElementType, 
                    inner.AsQueryable().ElementType, 
                    outerSelectorLambda.Body.Type, 

                    resultsSelectorLambda.Body.Type 
                },
                outer.Expression, 
                inner.AsQueryable().Expression, 
                System.Linq.Expressions.Expression.Quote(outerSelectorLambda), 
                System.Linq.Expressions.Expression.Quote(innerSelectorLambda), 
                System.Linq.Expressions.Expression.Quote(resultsSelectorLambda)));
    }


    //The generic overload.
    public static IQueryable<T> Join<T>(this IQueryable<T> outer, IEnumerable<T> inner, string outerSelector, string innerSelector, string resultsSelector, params object[] values)
    {
        return (IQueryable<T>)Join((IQueryable)outer, (IEnumerable)inner, outerSelector, innerSelector, resultsSelector, values);
    }

I have used the Join method as shown below :

       var q = Join(e1, e2, "Company_ID", "Company_ID",
        "new ( outer.Company_ID as CompanyId)"      );

But i get the error as shown below :

No generic method 'Join' on type 'System.Linq.Queryable' is compatible with the supplied type arguments and arguments. No type arguments should be provided if the method is non-generic.

Please Help .

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outerSelectorLambda.Body.Type

Shouldn't this be Body.ReturnType ?

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This return statement is too big. Break it up and look at the types with the debugger.