Get only the last result

Question

Hey. Why do I only get the last result with this code? 

foreach (DataGridViewRow dr in dgvOperation.Rows)
{
var query = @"GetFullText";
SqlCommand cmd = new SqlCommand(query, con);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("@Text", dr.Cells[2].Value.ToString());
cmd.Parameters.AddWithValue("@Klientnavn", txtKlientNavn.Text);

DataTable dt = new DataTable();
var sda = new SqlDataAdapter();
sda.SelectCommand = cmd;
sda.Fill(dt);
dgvOperation1.DataSource = dt;
}