how to prevents image not delete if image url exist another

if (OldImage.Exists){

 string connectionstring = "Server=MomalPC\\MOMAL;Database=Project;Trusted_Connection=True;"; SqlConnection conn = new SqlConnection(); conn.ConnectionString = connectionstring; conn.Open(); SqlDataAdapter sda = new SqlDataAdapter("Select * from Members where Number = '" + SearchID.Text + "'", conn); DataTable dtStock = new DataTable(); sda.Fill(dtStock); dataGridView1.DataSource = dtStock; conn.Close();

 

          if( 0 == dtStock.Rows.Count ) {

          // does not exist

         // DO not delete!! 

           Else{

         OldImage.Delete();

        } 

} 

 

}