Lập trình

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Data.SqlClient;

/// <summary>
/// Summary description for p312
/// </summary>

public class p312

{

private String connectionString;

public SqlConnection con;

//public SqlCommand cmd;

//public SqlDataReader rd;

public p312()

{

 connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionString"].ToString();

}

//Khai báo chuỗi kết nối có tham số

public p312(string strConnec)

{

this.connectionString = strConnec;

}

//Khai báo mở kết nối

public void openConnec()

{

con = new SqlConnection();

con.ConnectionString = connectionString;

con.Open();

}

//Khai báo đóng kết nối