Question

I know it may seem like an easy to solve problem, but I can’t find my fault in this piece of code. I’m returning int and Eclipse is telling me that ‘This method must return a result of type int’.

public static int getLastId(int table) {

    Connection connection = null;
    String url = "jdbc:postgresql://someServer:port/someDB";

    try {
        //Verbindung herstellen
        connection = DriverManager.getConnection(url, "someUser",
                "somePassword");
        } catch (SQLException e1) {
        //fehlerhafte Verbindung
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }

    try {
        //0 - source ; 1 - destination Table
        if(table == 0){

        Statement stmt = connection.createStatement();
        ResultSet lastId;
        lastId = stmt.executeQuery("SELECT index FROM table0 ORDER BY someIndex DESC LIMIT 1");
        String theLastId0 = "";
         while(lastId.next())
          {

              //System.out.print(lastId.getString("index"));
              theLastId0 = lastId.getString("index");

          }
          lastId.close();
          stmt.close();
          connection.close();
          int letzteId0 = Integer.parseInt(theLastId0);

        return letzteId0;

        }else if(table == 1){

            Statement stmt = connection.createStatement();
            ResultSet lastId;
            lastId = stmt.executeQuery("SELECT index FROM table1 ORDER BY someIndexDESC LIMIT 1");
            String theLastId1 = "";
              while(lastId.next())
              {

                  //System.out.print(lastId.getString("index"));
                  theLastId1 = lastId.getString("index");

              }
              lastId.close();
              stmt.close();
              connection.close();
              int letzteId1 = Integer.parseInt(theLastId1);

            return letzteId1;
            }

    } 
    catch (SQLException e) {

        System.out.println("Connection Failed! Check output console");
        e.printStackTrace();
        return -1;
    }
}

Answer 1

This method must Always return an int.

You must add the following else statement

else {
return 0;
}

after the else if because in your version you don’t return anything if your if AND your else if evaluates to false.