Simple Lambda2SQL converter

LambdaParser.cs

//
//  Program.cs
//
//  Author:
//       Benito Palacios Sánchez (aka pleonex) <benito356@gmail.com>
//
//  Copyright (c) 2015 Benito Palacios Sánchez (c) 2015
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
using System;
using System.Linq.Expressions;

namespace LambdaParser
{
    public static class Program
    {
        private class A
        {
            public int X { get; set; }
            public int Y { get; set; }
        }

        public static void Main()
        {
            Expression<Func<A, int, bool>> expression =  (a, p1) => a.X == 42 && a.Y == (a.X + p1);
            Console.WriteLine(PrintExpression(expression.Body));
        }

        private static string PrintExpression(Expression expression)
        {
            if (expression.NodeType == ExpressionType.MemberAccess)
                return (expression as MemberExpression).Member.Name;
            
            if (expression.NodeType == ExpressionType.Constant)
                return (expression as ConstantExpression).Value.ToString();

            if (expression.NodeType == ExpressionType.Parameter)
                return "%" + (Convert.ToInt32((expression as ParameterExpression).Name.Substring(1)) - 1);

            BinaryExpression expr = expression as BinaryExpression;
            string result = "(" + PrintExpression2(expr.Left);

            if (expression.NodeType == ExpressionType.Equal)
                result += " == ";

            if (expression.NodeType == ExpressionType.AndAlso)
                result += " AND ";

            if (expression.NodeType == ExpressionType.Add)
                result += "+";

            return result + PrintExpression2(expr.Right) + ")";
        }
    }
}

The output is: ((X == 42) AND (Y == (X+%0)))