Question

I took an video from you tube to Retrieving Data from SQL Server using C# and ADO.Net

http://www.youtube.com/watch?v=4kBXLv4h2ig&feature=related

I Do the same as him in the video…
I want to show data from an sql database in a DataGridView.

I get an error whit

da.Fill(dg);
dg.DataSource = dg.Tables[0];

I name my DataGridView dg…

Complete code

using System.Data.SqlClient;

namespace SQLconnection
 {
 public partial class Form1 : Form
{
    SqlConnection cs = new SqlConnection("Data Source=FRANK-PC\\SQLEXPRESS; Initial Catalog=Forc#; Integrated Security=TRUE");
    SqlDataAdapter da = new SqlDataAdapter();

    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        da.InsertCommand= new SqlCommand ("INSERT INTO tblContacts VALUES (@FirstName,@LastName)",    cs );
        da.InsertCommand.Parameters.Add("@FirstName", SqlDbType.VarChar).Value = txtFirstName.Text;
        da.InsertCommand.Parameters.Add("@LastName", SqlDbType.VarChar).Value = txtLastname.Text;

        cs.Open();
        da.InsertCommand.ExecuteNonQuery();
        cs.Close();
    }

    // Display data in dg
    private void button2_Click(object sender, EventArgs e)
    {
        da.SelectCommand = new SqlCommand("SELECT * FROM tblContacts", cs);
        da.Fill(dg);


        dg.DataSource = dg.Tables[0];
    }


}

}

Answer 1

The Fill method open/close connection implicitly but the problem is in name of dataGrdiView and DataTable/DataSet reference variable – dg

private void button2_Click(object sender, EventArgs e)
    {
        da.SelectCommand = new SqlCommand("SELECT * FROM tblContacts", cs);
        DataTable dt=new DataTable();
        da.Fill(dt);

        dg.DataSource = dt;
    }