Ponovo problem sa querijem

Code:

 public DataTable OdabirPrijavaKorisnika(string brojkartice)
        {
            
            SqlCeConnection con = new SqlCeConnection(@"Data Source = |DataDirectory|\fu.sdf");
            con.Open();
            SqlCeCommand cmd = new SqlCeCommand(" Select * from logovanje where brojkartice ='č10154_' "    , con);            
 
            SqlCeDataAdapter da = new SqlCeDataAdapter(cmd);
            DataTable tble = new DataTable();
            da.Fill(tble);
            con.Close();
            return tble;
        }

Code:

 public DataTable OdabirPrijavaKorisnika(string brojkartice)
        {
            
            SqlCeConnection con = new SqlCeConnection(@"Data Source = |DataDirectory|\fu.sdf");
            con.Open();
                      
  SqlCeCommand cmd = new SqlCeCommand(" Select * from logovanje where brojkartice=@brojkartice", con);          

            SqlCeDataAdapter da = new SqlCeDataAdapter(cmd);
            DataTable tble = new DataTable();
            da.Fill(tble);
            con.Close();
            return tble;
        }

Code:

 public DataTable OdabirPrijavaKorisnika(string brojkartice)
        {
            
            SqlCeConnection con = new SqlCeConnection(@"Data Source = |DataDirectory|\fu.sdf");
            con.Open();
                      
  SqlCeCommand cmd = new SqlCeCommand(" Select * from logovanje where brojkartice=@brojkartice", con);          

// kucam napamet
cmd.Parametars.Add("brojkartice", varchar).value = brojkartice

            SqlCeDataAdapter da = new SqlCeDataAdapter(cmd);
            DataTable tble = new DataTable();
            da.Fill(tble);
            con.Close();
            return tble;
        }