1. 要在專案中新增一個基於服務的資料庫或本地資料庫檔案；

2. 在程式碼執行開始先執行如下程式碼，否則資料庫表中看不到執行的語句 

           string dataDir = AppDomain.CurrentDomain.BaseDirectory;
            if(dataDir.EndsWith(@"\bin\Debug\") || dataDir.EndsWith(@"\bin\Release\"))
            {
                dataDir = System.IO.Directory.GetParent(dataDir).Parent.Parent.FullName;
                AppDomain.CurrentDomain.SetData("DataDirectory", dataDir);
            }
 

3. 定義連線字串：@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True;User Instance=True"

4. 編寫程式：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;

namespace 資料庫1
{
    class Program
    {
        static void Main(string[] args)
        {
            string dataDir = AppDomain.CurrentDomain.BaseDirectory;
            if(dataDir.EndsWith(@"\bin\Debug\") || dataDir.EndsWith(@"\bin\Release\"))
            {
                dataDir = System.IO.Directory.GetParent(dataDir).Parent.Parent.FullName;
                AppDomain.CurrentDomain.SetData("DataDirectory", dataDir);
            }


            string 
 
[email protected]"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True;User Instance=True";
            using (SqlConnection conn = new SqlConnection(connStr))
            {
                conn.Open();
                using (SqlCommand cmd = conn.CreateCommand())
                {
                    string username = Convert.ToString(System.DateTime.Now.Millisecond);
                    cmd.CommandText = "insert into t_user (username,password) values ('" + username + "', '3333')";
                    cmd.ExecuteNonQuery();
                    Console.WriteLine("執行成功");


                    cmd.CommandText = "select * from t_user where username='" + username + "'";
                    using (SqlDataReader reader = cmd.ExecuteReader())
                    {
                        if (reader.Read())
                        {
                            string password = reader.GetString(reader.GetOrdinal("password"));
                            Console.WriteLine("使用者： " + username + ", 密碼： " + password);
                        }
                        else
                        {
                            Console.WriteLine("沒有這個使用者 " + username);
                        }
                    }

                }
            }

            Console.ReadKey();


        }
    }
}