C#SQL数据库操作

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Data.SqlClient;namespace 数据库学习{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private void button1_Click(object sender, EventArgs e)        {            using (SqlConnection comn = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True;User Instance=True"))//Database1.mdf   换成自己的MDF文件    Data Source = .\SQLEXPRESS 针对开发版的SQL            {                comn.Open();                using (SqlCommand cmd = comn.CreateCommand())                {                    cmd.CommandText = "select * from T_Users";                    cmd.ExecuteNonQuery();                }            }        }        private void Form1_Load(object sender, EventArgs e)        {            //神奇代码            string dataDir = AppDomain.CurrentDomain.BaseDirectory;            if (dataDir.EndsWith(@"\bin\Debug\") || dataDir.EndsWith(@"\bin\Debug\"))            {                dataDir = System.IO.Directory.GetParent(dataDir).Parent.Parent.FullName;                AppDomain.CurrentDomain.SetData("DataDirectory", dataDir);            }        }    }}