database

1.access数据库的连接串：
OleDbConnection con = new OleDbConnection("provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("") + "http://www.cnblogs.com/dannyboy/admin/file://App_Data//danny.mdb");
        con.Open();

2.OleDbDataReader用法：
  OleDbDataReader rd ;
  rd= cmd.ExecuteReader();
 
using System.Data.SqlClient;

3.Dataset的用法
OleDbConnection con = new OleDbConnection("");
        con.Open();
        OleDbDataAdapter dad = new OleDbDataAdapter("select * from Select_Question", con);
        DataSet ds = new DataSet();
        dad.Fill(ds, "dannyboy");
       // this .Label2 .Text = ds.Tables["dannyboy"].Rows[1][1].ToString();
        con.Close();

/////////////////////////////////////////////////
SQL Server
"Data Source=(local);Integrated Security=SSPI;Database=Northwind";
"Data Source = DANNYGIRL;User ID=sa;Password=139020;Database = dannyboy;";

  static string strConnection = "Data Source=.;Initial Catalog=qiujiting;Integrated Security=True";
 
1。执行建立一个表
string con = "Data Source = DANNYGIRL;User ID=sa;Password=139020;Database = dannyboy;";
SqlConnection com = new SqlConnection(con);
com.Open();
string strCom = @"create table personnel (PNumber char(10) ,PName char(10),PPay int,PDep char(10) , primary key (PNumber))";
SqlCommand cmd = new SqlCommand(strCom,com);
cmd.ExecuteNonQuery();
com .Close();  
:：
2。用dataGrid显示一张表
 string con = "Data Source = DANNYGIRL;User ID=sa;Password=139020;Database = dannyboy;";
            SqlConnection com = new SqlConnection(con);
            com.Open();
            SqlDataAdapter ada = new SqlDataAdapter("select * from personnel", com);
            DataSet ds = new DataSet();
            ada.Fill(ds, "dannyboy");

            this.dataGrid1.DataSource = ds.Tables["dannyboy"].DefaultView;

            com.Close(); 

3。datareader的用法。
 string con = "Data Source = DANNYGIRL;User ID=sa;Password=139020;Database = dannyboy;";
            SqlConnection com = new SqlConnection(con);
            com.Open();
            string strCom = @"select * from personnel";

           SqlCommand cmd = new SqlCommand(strCom,com);
           SqlDataReader dr= cmd.ExecuteReader();

            MessageBox.Show(dr.FieldCount.ToString());
         int i = 0;
            while (dr.Read())
         {
             MessageBox.Show(dr.GetString(i++));
             dr.Read();
         } 
            com.Close();
           
        }

/////////////////////
 string sSex="F";
        if (this.RadioButton1.Checked == true) sSex = "M";
        connectionstring cLinkstring = new connectionstring();
        SqlConnection com = new SqlConnection(cLinkstring.getconnectionstring());
        com.Open();
        string strCom = "";
       
        SqlCommand cmd = new SqlCommand(strCom, com);
        cmd.ExecuteNonQuery();
        com.Close();