I want to load the database table data on datagridview.

There are a number of ways to do this, one is to issue the same SELECT query you have been doing to retrieve all the rows, but to add a WHERE clause:

SELECT * FROM myTable WHERE ID=17

(only preferably, with a parameterised query:

using (SqlConnection con = new SqlConnection(strConnect))
    {
    con.Open();
    using (SqlDataAdapter da = new SqlDataAdapter("SELECT MyColumn1, MyColumn2 FROM myTable WHERE mySearchColumn = @SEARCH", con))
        {
        da.SelectCommand.Parameters.AddWithValue("@SEARCH", myTextBox.Text);
        DataTable dt = new DataTable();
        da.Fill(dt);
        myDataGridView.DataSource = dt;
        }
    }

But there is another way, which can be a lot more flexible (and much quicker from the user POV) - use a DataView as well:

using (SqlConnection con = new SqlConnection(strConnect))
    {
    con.Open();
    using (SqlDataAdapter da = new SqlDataAdapter("SELECT MyColumn1, MyColumn2 FROM myTable WHERE mySearchColumn = @SEARCH", con))
        {
        da.SelectCommand.Parameters.AddWithValue("@SEARCH", myTextBox.Text);
        DataTable dt = new DataTable();
        da.Fill(dt);
        myClassLevelDataView = new DataView(dt);
        myDataGridView.DataSource = dv;
        }
    }

Then when you want to change it, you just set the RowFilter property of the DataView:

myClassLevelDataView.RowFilter = "Text LIKE '%" + myTextBox.Text + "%'";

And magic happens! :laugh: