MySQL数据库连接不起作用

Question

First time using an external database with android and i'm trying to set up the database connections. I created a basic table in the database just for testing purposes and am trying to connect and insert some data. This is my code:

public class DBInterface {
//TODO: Fix the database connections

    private Connection conn = null;
    private  Statement statement = null;



    public void connectToDatabase(){
        Log.d("myTag", "This is my messagestart");
        try {

            Class.forName("com.mysql.jdbc.Driver").newInstance();
            conn = DriverManager.getConnection("jdbc:mysql://mysql.**.***.***.***:3306", "DB_USER", "DB_PASSWORD");
            statement = conn.createStatement();
            statement.executeUpdate("INSERT INTO test (test) VALUES (15)");
            Log.d("myTag", "This is my message");


        } catch (SQLException ex) {
            Log.d("myTag", "SQLException: " + ex.getMessage());
            Log.d("myTag","SQLState: " + ex.getSQLState());
            Log.d("myTag","VendorError: " + ex.getErrorCode());
        }catch(Exception e){e.printStackTrace();}
    }

and I call it in the onCreate of the MainActivity:

         DBInterface db = new DBInterface();
         db.connectToDatabase();
         Log.d("myTag", "This is my message2");

No data is inserted but i also don't get any errors, i put the log messages in to try and see where it was getting to and the only output to the log is:

10-31 16:13:41.481 9918-9918/com.jacksteel.comp4 D/myTag: This is my messagestart

10-31 16:13:41.486 9918-9918/com.jacksteel.comp4 D/myTag: This is my message2

Answer 1

Not a direct answer, but you never want to connect your app directly to your database. Instead you should write some scripts on your server to perform INSERT, SELECT, UPDATE , DELETE.

Your app will then send requests to these scripts to execute the queries.