C# - EX01 - MSSQL 연동 ( 콘솔 버젼 )

--10/13
using System;
using System.Collections.Generic;
using System.Text;

using System.Data; // Data 연동에 필요한 공통 객체 포함
using System.Data.SqlClient;  // SQL Server Provider 객체 포함

namespace Ex01
{
    class Program
    {
        static void Main(string[] args)
        {
            //1. 연결 객체 생성 및 연결 정보
            SqlConnection conn = new SqlConnection();

            //--------------- 다른 방법  ---------------------------------------------------------
            //conn.ConnectionString = "SERVER=.;DATABASE=Northwind;INTEGRATED SECURITY=SSPI;";
            //--------------- 다른 방법 ----------------------------------------------------------
            //conn.ConnectionString = "SERVER=172.16.7.1,1433;" +      // 서버 정보
            //                        "DATABASE=Northwind;" +      // DB 정보
            //                        "INTEGRATED SECURITY=SSPI;";           // 계정 정보(윈도우 계정)
            //                        "UID=sa;PWD=knit";         // 아아뒤 / 비번 (SQL 계종)
            //--------------- 다른 방법 ----------------------------------------------------------

            conn.ConnectionString = "DATA SOURCE=172.16.7.1,1433;" +      // 서버 정보
                                  "INITIAL CATALOG=Northwind;" +      // DB 정보
                        //    "INTEGRATED SECURITY=SSPI;";           // 계정 정보(윈도우 계정)
                                   "USER ID=sa;PASSWORD=knit";         // 아아뒤 / 비번 (SQL 계종)

            //-----------------------------------------------------------------------------------
           

            //2. 명령 객체 생성 및 [SQL, 연결객체] 설정
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;
            cmd.CommandText = "SELECT customerid, companyname, contactname FROM customers ";

          //  cmd.CommandText = "SELECT customerid FROM customers ";

            //3. 연결 열기
            conn.Open();

            //4. 명령 실행
            SqlDataReader reader = cmd.ExecuteReader();

            //5. 결과가 있다면 결과를 처리
            while (reader.Read())
            {
                Console.WriteLine("[{0}][{1}][{2}]",
                               reader.GetString(0),
                               reader[1],
                               reader["companyname"]);
            }

//////////////////////    전부다 같은 표현이다   /////////////////
// while (reader.Read())           
//         {     reader.GetString(0),reader.GetString(1),reader.GetString(2) );   }
// while (reader.Read())         
 //         {     readerreader[0], reader[1], reader[2] );    }
// while (reader.Read())       
//          {     readerreader["companyname"],reader["customerid"],reader["contactname "] );    }
//////////////////////////////////////////////////////////////////////////

            //6. 연결 닫기
            reader.Close();
            conn.Close();
        } 
    }
}