C#

using System;
using System.Reflection;
namespace SqlSentence
{ 
    public static class SqlString
    {
        public static string SELECT(this string This, params string[] columnName)
        {
            string s=" SELECT ";
            for (int i = 0; i < columnName.Length; i++)
            {
                s += columnName[i] + ",";
            }
            return This + s.Substring(0, s.Length - 1);
        }

        public static string FROM(this string This, string tableName)
        {
            return This + " FROM " + tableName;
        }

        public static string AS(this string This, string target)
        {
            return This + " AS " + target;
        }

        public static string WHERE(this string This, string term)
        {
            return This + " WHERE " + term;
        }

        public static string EQUAL(this string This, string value)
        {
            return This + " = " + value;
        }

        public static string EQUAL(this string This)
        {
            return This + " = ";
        }

        public static string PARAMETERS(this string This, string value)
        {
            return This + "@" + value;
        }

        public static string AND(this string This, string where)
        {
            return This + " AND " + where;
        }
    }
}


using System;
using System.Windows.Forms;
using System.Data.SqlClient;
using SqlSentence;
//using System.Collections.Generic;

namespace WindowsFormsApplication4
{

    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            SqlCommand cmd = new SqlCommand();
            cmd.CommandText = cmd.CommandText.SELECT("Name", 
                                     "sex".AS("Sex") , "ID").   
                                     FROM("customer").WHERE("name".EQUAL 
                                     ("'zhangshan'").AND("sex".EQUAL
                                     ("'boy'")));
            SqlCommand otherCmd = new SqlCommand();
            otherCmd.CommandText = otherCmd.CommandText.
                                            SELECT("name", 
                                            "sex".AS("Sex"), 
                                            "ID").
                                            FROM("customer").
                                            WHERE("name".EQUAL
                                            ("'zhangshan'").AND
                                            ("name".EQUAL().
                                            PARAMETERS("value")));
        }
    }
}