C# MS-SQL 연동

using System;
using System.Data.SqlClient;
 
namespace CS_ConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            SqlConnection con = new SqlConnection();
            //SqlCommand cmd = new SqlCommand();
            Console.WriteLine("연결시도");
 
            con.ConnectionString = "server=210.119.12.79,1617; database=ADO; uid=sa; pwd=it17";
 
            con.Open();
            SqlCommand cmd = new SqlCommand("SELECT * FROM ADO", con);
 
            Console.WriteLine("DB 연결 성공");
 
            /*
            Console.WriteLine("테이블 만들기 시도");
            cmd.Connection = con;
            cmd.CommandText = "CREATE table 성적표 (" +
                "번호 int primary key," +
                "이름 varchar(6) not null," +
                "국어 int," +
                "영어 int," +
                "수학 int)";
            
 
            cmd.ExecuteNonQuery();
            Console.WriteLine("테이블 만들기 성공");
            */
 
            Console.WriteLine("데이터 추가 시도");
            cmd.CommandText = "INSERT INTO 성적표 VALUES(1, '추경호', 95, 100, 85)";
            cmd.ExecuteNonQuery();
 
            cmd.CommandText = "INSERT INTO 성적표 VALUES(2, '조수현', 100, 80, 85)";
            cmd.ExecuteNonQuery();
            con.Close();
        }
    }
}

using System;
using System.Data.SqlClient;
 
namespace CS_ConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            SqlConnection con = new SqlConnection();
            Console.WriteLine("DB 연결시도");
            con.ConnectionString = "server=210.119.12.79,1617; database=ADO; uid=sa; pwd=it4321";
            con.Open();
            Console.WriteLine("DB 연결 성공");
 
            SqlCommand cmd = new SqlCommand(); 
            
            cmd.Connection = con;
 
            Display(cmd);
 
            cmd.CommandText = "update 성적표 set 영어=@영어,수학=@수학 " +
                "where 이름='조수현'";
            cmd.Parameters.AddWithValue("@영어", 99);
            cmd.Parameters.AddWithValue("@수학", 88);
            cmd.ExecuteNonQuery();
            Display(cmd);
 
            cmd.CommandText = "DELETE FROM 성적표 WHERE 이름 = @이름";
            cmd.Parameters.AddWithValue("@이름", "조수현");
            cmd.ExecuteNonQuery();
            Display(cmd);
 
            con.Close();
        }
 
        static void Display(SqlCommand cmd)
        {
            SqlDataReader sqlReader = null;
            cmd.CommandText = "select * from 성적표";
            sqlReader = cmd.ExecuteReader();
 
            for (int i = 0; i < sqlReader.FieldCount; i++)
            {
                Console.Write("{0,7}", sqlReader.GetName(i));
            }
            Console.WriteLine();
 
            string field = "";
            while (sqlReader.Read())
            {
                for (int i = 0; i < sqlReader.FieldCount; i++)
                {
                    field = sqlReader.GetName(i);
                    Console.Write("{0,8}", sqlReader[field]);
                }
                Console.WriteLine();
            }
            sqlReader.Close();
        }
    }
}

윈폼

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
 
namespace DB3
{
    public partial class Form1 : Form
    {
        SqlConnection con;
        SqlDataAdapter mSqlDataAdapter;
        DataSet mDataSet;
        DataTable mDataTable;
 
        public Form1()
        {
            InitializeComponent();
 
            try
            {
                if (con == null)
                    con = new SqlConnection();
 
                textBox1.AppendText("DB연결 시도\r\n");
                con.ConnectionString =
                "server=PKNU1\\SQLEXPRESS;database=ADO;uid=sa;pwd=1234";
                con.Open();
                textBox1.AppendText("DB연결 성공\r\n");
            }
            catch { textBox1.AppendText("DB연결 실패\r\n"); }
            updateDataView();
        }
 
        public void updateDataView()
        {
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = con;
            cmd.CommandText = "select * from 성적표";
 
            mSqlDataAdapter = new SqlDataAdapter();
            mSqlDataAdapter.SelectCommand = cmd;
 
            mDataSet = new DataSet("성적관리");
            mSqlDataAdapter.Fill(mDataSet, "성적표");
 
            mDataTable = mDataSet.Tables["성적표"];
            dataGridView1.DataSource = mDataTable;
        }
    }
}