using System;  
using System.Data.SqlClient;  
using System.Data;  
namespace DataAdapterExample  
{  
    public partial class DataAdapterDemo : System.Web.UI.Page  
    {  
        protected void Page_Load(object sender, EventArgs e)  
        {  
            using (SqlConnection conn = new SqlConnection("data source=.; database=items; integrated security=SSPI"))  
            {  
                SqlDataAdapter da = new SqlDataAdapter("Select * from items", conn);  
                DataSet s = new DataSet();  
                da.Fill(s);  
                GridView1.DataSource = s;  
                GridView1.DataBind();  
            }  
        }  
    }  
}  ​

using System;  
using System.Data.SqlClient;  
using System.Data;  
namespace DataSetDemo  
{  
    public partial class DataSetExample : System.Web.UI.Page  
    {  
        protected void Page_Load(object sender, EventArgs e)  
        {  
            using (SqlConnection conn = new SqlConnection("data source=.; database=employee; integrated security=SSPI"))  
            {  
                SqlDataAdapter da = new SqlDataAdapter("Select * from employee", conn);  
                DataSet d = new DataSet();  
                da.Fill(d);  
                GridView1.DataSource = d;  
                GridView1.DataBind();  
            }  
        }  
    }  
}​

protected void BinddataTable()
{
    SqlConnection con = new SqlConnection("your database connection string");
    con.Open();
    SqlCommand cmd = new SqlCommand("Write your query or procedure", con);
    SqlDataAdapter da = new SqlDataAdapter(cmd);
    DataTable dt = new DataTable();
    da.Fill(dt);
    grid.DataSource = dt;
    grid.DataBind();
}

// Create a command builder object
SqlCommandBuilder builder = new SqlCommandBuilder(adapter);

DataView custDV = new DataView(customerDS.Tables["Customers"],
"Country = 'USA'",
"ContactName",
DataViewRowState.CurrentRows);
DataView custDV = customerDS.Tables["Customers"].DefaultView;

private void frmSqlCommand_Load(object sender, EventArgs e)
{
    //Sample 03: Open Database Connection
    String con_string = Properties.Settings.Default.ConStrPubs;
    pubs_db_connection = new SqlConnection(con_string);
    pubs_db_connection.Open();
    //Sample 04: Form the Command Object
    SqlCommand cmd = new SqlCommand();
    cmd.CommandText = "Select Count(*) as Count from Titles";
    cmd.Connection = pubs_db_connection;
    //Sample 05: Execute the Command & retrive scalar value
    lblTotal.Text = System.Convert.ToString(cmd.ExecuteScalar());
}

SqlDataAdapter da;
DataSet ds;
string strconn = "Data Source=YourServerName;Initial Catalog=EMP;Integrated Security=True";
private void Form1_Load(object sender, EventArgs e)
{
    da = new SqlDataAdapter("select * from userdet", strconn);
    ds = new System.Data.DataSet();
    da.Fill(ds);
    dataGridView1.DataSource = ds.Tables[0];
}

public void CallExecuteNonQuery()
{
    SqlConnection conn = new SqlConnection();
    conn.ConnectionString = ConfigurationManager.ConnectionStrings["connString"].ConnectionString;
    try
    {
        SqlCommand cmd = new SqlCommand();
        cmd.Connection = conn;
        cmd.CommandText = "DELETE FROM EMP WHERE DEPTNO = 40";
        cmd.CommandType = CommandType.Text;
        conn.Open();
        Int32 RowsAffected = cmd.ExecuteNonQuery();
        MessageBox.Show(RowsAffected + " rows affected", "Message");
        cmd.Dispose();
        conn.Dispose();
    }
    catch(Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}

DataRelation drel;
drel = new DataRelation("All", ds.Tables[0].Columns[0], ds.Tables[1].Columns[0]);

XmlReader xmlreader = cmd.ExecuteXmlReader();
XmlDocument xdoc = new XmlDocument();

public void ExecuteScalarExample()  
{  
    SqlConnection con = new SqlConnection();  
    con.ConnectionString = ConfigurationManager.ConnectionStrings["conString"].ConnectionString;  
    try  
    {  
        SqlCommand cd = new SqlCommand();  
        cd.Connection = con;  
        cd.CommandText = "SELECT SUM(SALARY) FROM EMPLOYEE";  
        cd.CommandType = CommandType.Text;  
        con.Open();  
        Int32 SalaryTotal = Convert.ToInt32(cd.ExecuteScalar());  
        MessageBox.Show("Total Salary of the employee is : " + SalaryTotal.ToString());  
        cd.Dispose();  
        con.Dispose();  
    }  
    catch (Exception ex)  
    {  
        MessageBox.Show(ex.Message);  
    }  
}​

"Server=MSSQL1;Database=Institute;Integrated Security=true;​

"Persist Security Info=False;User ID=Harsh;Password=xyz@123;Initial Catalog=Institute;Server=MySqlServer"

using System;
using System.Data;
using System.Data.SqlClient;
using System.Xml.Serialization;
using System.IO;
public partial class Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        SqlConnection conn = new SqlConnection("Data Source=data_source_name;Initial Catalog=employee;Integrated Security=True");  //Create connection object
        SqlDataAdapter da = new SqlDataAdapter("select * from emp", conn);  //DataAdapter creation
        DataSet s = new DataSet();
        da.Fill(s);  
        FileStream fObj = new FileStream("C:\\demo.xml", FileMode.Create);   // Create a XML file
        XmlSerializer sObj = new XmlSerializer(typeof(DataSet));
        sObj.Serialize(fObj, s);  //Serialization of a DataSet
        fObj.Close();
    }
}