1,引用命名空间

　　　using System.Data.SqlClient;

2，定义五大对象

        SqlConnection con = null;

        SqlCommand cmd = null;

        SqlDataAdapter adapter = null;

        SqlDataReader reader = null;

        DataSet set = null;

3，给五大对象赋值

（1）SqlConnection

　　  第一种方式：使用命令构建者连接数据库

        SqlConnectionStringBuilder conStr2 = new SqlConnectionStringBuilder();

        conStr2.DataSource = @"TARENA-54\SQLEXPRESS";

        conStr2.InitialCatalog = "others";

        conStr2.IntegratedSecurity = true;

        使用时 ：con.ConnectionString =conStr2.ToString();

　　  第二种方式：直接将数据库连接写出来

　　　通过用户名和密码：string ;"

　　　通过window验证：string str=@"Data Source=localhost\SQLEXPRESS;Initial Catalog=others;Integrated Security=True";

  　　第三种方式：根据配置文件的连接串连接数据库

        在cs代码中获取连接串的方式：

　　  con.ConnectionString = ConfigurationManager.ConnectionStrings["mySql"].ToString();

       con.ConnectionString =ConfigurationManager.ConnectionStrings["db"].ConnectionString .ToString();

　在配置文件中的配置为：

<configuration>

  <connectionStrings >

    <add name ="mySql" connectionString ="Data Source=TARENA-54\SQLEXPRESS;Initial Catalog=others;Integrated Security=True"/>

      <add name="mySql" connectionString="database=SatisfiedCheckDBS;server=HQMSQLClustern\PPSDBInst3;uid=PPSUser;pwd=3007$PPSSQLClient#;"/>

  </connectionStrings>

</configuration>

 

（2）comment的常用法：

     com = new SqlCommand();

            com.Connection = con;

            com.CommandText = "select * from obi";

            com.CommandType = CommandType.Text;

            while (reader.Read())

            {

                ListBox1.Items.Add(reader.GetValue(0).ToString());

                ListBox2.Items.Add(reader.GetValue(1).ToString());

                ListBox3.Items.Add(reader.GetValue(2).ToString());

            }

            reader.Close();

4使用方式

第一种：

            con = new SqlConnection();

            con.ConnectionString = str;

            con.Open();

             

            cmd = new SqlCommand("select * from obi", con);

            reader = cmd.ExecuteReader();

            while (reader.Read())

            {

                comboBox1.Items.Add(reader.GetValue(0));

            }

第二种：

     con = new SqlConnection(@"Data Source=TARENA-54\SQLEXPRESS;Initial Catalog=others;Integrated Security=True");

     con.Open();

            cmd = new SqlCommand("insert obi values(" + IDStr + ",'" + strstr + "','" + dateStr + "')", con);

            cmd.ExecuteNonQuery();

第三种：

     adapter = new SqlDataAdapter(@"select * from obi", con);

            ds = new DataSet();

            adapter .Fill(ds, "obi");  //obi是表名

            listBox1.Items.Add("obi");   //在listBox1显示

     dataGridView1.DataSource = ds.Tables["obi"] ;//在dataGridView1显示