Question

I have a problem regarding the database for my application. The database is supposed to be available when my application starts, however currently the database will only appear on the ddms when I enters data that is needed to be inserted into the database which is incorrect. Anyone have an idea on solving my problem? Any help will be greatly appreciated! Thanks in advance.

Answer 1

on start of your app you need to check whether DB is already there in ddms or not.. if DB is there then you have to configure it so after that all will be fine

here is complete code..

package com.MyPackage;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;

import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class AnyDBAdapter {

private static final String TAG = "AnyDBAdapter";
private DatabaseHelper mDbHelper;
private static SQLiteDatabase mDb;

//make sure this matches the 
//package com.MyPackage;
//at the top of this file
private static String DB_PATH = "/data/data/com.MyPackage/databases/";

//make sure this matches your database name in your assets folder
// my database file does not have an extension on it 
// if yours does
// add the extention
private static final String DATABASE_NAME = "data";

//Im using an sqlite3 database, I have no clue if this makes a difference or not
private static final int DATABASE_VERSION = 3;

private final Context adapterContext;

public AnyDBAdapter(Context context) {
    this.adapterContext = context;
}

public AnyDBAdapter open() throws SQLException {
    mDbHelper = new DatabaseHelper(adapterContext);

    try {
        mDbHelper.createDataBase();
    } catch (IOException ioe) {
        throw new Error("Unable to create database");
    }

    try {
        mDbHelper.openDataBase();
    } catch (SQLException sqle) {
        throw sqle;
    }
    return this;
}
//Usage from outside
// AnyDBAdapter dba = new AnyDBAdapter(contextObject); //in my case contextObject is a  map
// dba.open();
// Cursor c = dba.ExampleSelect("Rawr!");
// contextObject.startManagingCursor(c);
// String s1 = "", s2 = "";
// if(c.moveToFirst())
// do {
//  s1 = c.getString(0);
//  s2 = c.getString(1);
//  } while (c.moveToNext());
// dba.close();
public Cursor ExampleSelect(string myVariable)
{
    String query = "SELECT locale, ? FROM android_metadata";
    return mDb.rawQuery(query, new String[]{myVariable});
}

//Usage
// AnyDBAdatper dba = new AnyDBAdapter(contextObjecT);
// dba.open();
// dba.ExampleCommand("en-CA", "en-GB");
// dba.close();
public void ExampleCommand(String myVariable1, String myVariable2)
{
    String command = "INSERT INTO android_metadata (locale) SELECT ? UNION ALL SELECT  ?";
    mDb.execSQL(command, new String[]{ myVariable1, myVariable2});
}

public void close() {
    mDbHelper.close();
}

private static class DatabaseHelper extends SQLiteOpenHelper {

    Context helperContext;

    DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        helperContext = context;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        Log.w(TAG, "Upgrading database!!!!!");
        //db.execSQL("");
        onCreate(db);
    }

    public void createDataBase() throws IOException {
        boolean dbExist = checkDataBase();
        if (dbExist) {
        } else {

            //make sure your database has this table already created in it
            //this does not actually work here
            /*
             * db.execSQL("CREATE TABLE IF NOT EXISTS \"android_metadata\" (\"locale\"     TEXT DEFAULT 'en_US')"
             * );
             * db.execSQL("INSERT INTO \"android_metadata\" VALUES ('en_US')"
             * );
             */
            this.getReadableDatabase();
            try {
                copyDataBase();
            } catch (IOException e) {
                throw new Error("Error copying database");
            }
        }
    }

    public SQLiteDatabase getDatabase() {
        String myPath = DB_PATH + DATABASE_NAME;
        return SQLiteDatabase.openDatabase(myPath, null,
                SQLiteDatabase.OPEN_READONLY);
    }

    private boolean checkDataBase() {
        SQLiteDatabase checkDB = null;
        try {
            String myPath = DB_PATH + DATABASE_NAME;
            checkDB = SQLiteDatabase.openDatabase(myPath, null,
                    SQLiteDatabase.OPEN_READONLY);
        } catch (SQLiteException e) {
        }
        if (checkDB != null) {
            checkDB.close();
        }
        return checkDB != null ? true : false;
    }

    private void copyDataBase() throws IOException {

        // Open your local db as the input stream
        InputStream myInput = helperContext.getAssets().open(DATABASE_NAME);

        // Path to the just created empty db
        String outFileName = DB_PATH + DATABASE_NAME;

        // Open the empty db as the output stream
        OutputStream myOutput = new FileOutputStream(outFileName);

        // transfer bytes from the inputfile to the outputfile
        byte[] buffer = new byte[1024];
        int length;
        while ((length = myInput.read(buffer)) > 0) {
            myOutput.write(buffer, 0, length);
        }

        // Close the streams
        myOutput.flush();
        myOutput.close();
        myInput.close();
    }

    public void openDataBase() throws SQLException {
        // Open the database
        String myPath = DB_PATH + DATABASE_NAME;
        mDb = SQLiteDatabase.openDatabase(myPath, null,
                SQLiteDatabase.OPEN_READWRITE);
    }

    @Override
    public synchronized void close() {

        if (mDb != null)
            mDb.close();

        super.close();

    }
}

}