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copied!<p>Here is the solution I eventually ended up implementing. It's kind of a mash-up from info gained in the Commonsware books, and some stuff around the web that I wish I bookmarked cause I want to give credit:</p> <p>For each type of data that I need to pull from the db, I create an "adapter" class (not subclassed from anything). These adapter classes hold all of the methods necessary for accessing the db for that piece of info. For example, if I had three tables in my db:</p> <ol> <li>Cars</li> <li>Boats</li> <li>Motorcycles</li> </ol> <p>I would have three adapters that would look similar to the following(I'm only putting in one as a demo, but the idea is the same for each):</p> <pre><code>public class CarsDBAdapter { public static final String ROW_ID = "_id"; public static final String NAME = "name"; public static final String MODEL = "model"; public static final String YEAR = "year"; private static final String DATABASE_TABLE = "cars"; private DatabaseHelper mDbHelper; private SQLiteDatabase mDb; private final Context mCtx; private static class DatabaseHelper extends SQLiteOpenHelper { DatabaseHelper(Context context) { super(context, DBAdapter.DATABASE_NAME, null, DBAdapter.DATABASE_VERSION); } @Override public void onCreate(SQLiteDatabase db) { } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { } } /** * Constructor - takes the context to allow the database to be * opened/created * * @param ctx * the Context within which to work */ public CarsDBAdapter(Context ctx) { this.mCtx = ctx; } /** * Open the cars database. If it cannot be opened, try to create a new * instance of the database. If it cannot be created, throw an exception to * signal the failure * * @return this (self reference, allowing this to be chained in an * initialization call) * @throws SQLException * if the database could be neither opened or created */ public CarsDBAdapter open() throws SQLException { this.mDbHelper = new DatabaseHelper(this.mCtx); this.mDb = this.mDbHelper.getWritableDatabase(); return this; } /** * close return type: void */ public void close() { this.mDbHelper.close(); } /** * Create a new car. If the car is successfully created return the new * rowId for that car, otherwise return a -1 to indicate failure. * * @param name * @param model * @param year * @return rowId or -1 if failed */ public long createCar(String name, String model, String year){ ContentValues initialValues = new ContentValues(); initialValues.put(NAME, name); initialValues.put(MODEL, model); initialValues.put(YEAR, year); return this.mDb.insert(DATABASE_TABLE, null, initialValues); } /** * Delete the car with the given rowId * * @param rowId * @return true if deleted, false otherwise */ public boolean deleteCar(long rowId) { return this.mDb.delete(DATABASE_TABLE, ROW_ID + "=" + rowId, null) > 0; //$NON-NLS-1$ } /** * Return a Cursor over the list of all cars in the database * * @return Cursor over all cars */ public Cursor getAllCars() { return this.mDb.query(DATABASE_TABLE, new String[] { ROW_ID, NAME, MODEL, YEAR }, null, null, null, null, null); } /** * Return a Cursor positioned at the car that matches the given rowId * @param rowId * @return Cursor positioned to matching car, if found * @throws SQLException if car could not be found/retrieved */ public Cursor getCar(long rowId) throws SQLException { Cursor mCursor = this.mDb.query(true, DATABASE_TABLE, new String[] { ROW_ID, NAME, MODEL, YEAR}, ROW_ID + "=" + rowId, null, null, null, null, null); if (mCursor != null) { mCursor.moveToFirst(); } return mCursor; } /** * Update the car. * * @param rowId * @param name * @param model * @param year * @return true if the note was successfully updated, false otherwise */ public boolean updateCar(long rowId, String name, String model, String year){ ContentValues args = new ContentValues(); args.put(NAME, name); args.put(MODEL, model); args.put(YEAR, year); return this.mDb.update(DATABASE_TABLE, args, ROW_ID + "=" + rowId, null) >0; } } </code></pre> <p>So if you imagine I have one of these classes "adapters" for each table.</p> <p>When my app splash screen starts, I use the technique presented <a href="http://androidforbeginners.blogspot.com/2010/01/creating-multiple-sqlite-database.html">Android For Beginners: Creating multiple SQLite Tables for Android</a></p> <p>So my main DBAdapter (which is responsible for creating all of my tables in a single db) looks like this:</p> <pre><code>public class DBAdapter { public static final String DATABASE_NAME = "stuffIOwn"; //$NON-NLS-1$ public static final int DATABASE_VERSION = 1; private static final String CREATE_TABLE_CARS = "create table cars (_id integer primary key autoincrement, " //$NON-NLS-1$ + CarsDBAdapter.NAME+ " TEXT," //$NON-NLS-1$ + CarsDBAdapter.MODEL+ " TEXT," //$NON-NLS-1$ + CarsDBAdapter.YEAR+ " TEXT" + ");"; //$NON-NLS-1$ //$NON-NLS-2$ private static final String CREATE_TABLE_BOATS = "create table boats (_id integer primary key autoincrement, " //$NON-NLS-1$ +BoatsDBAdapter.NAME+" TEXT," //$NON-NLS-1$ +BoatsDBAdapter.MODEL+" TEXT," //$NON-NLS-1$ +BoatsDBAdapter.YEAR+" TEXT"+ ");"; //$NON-NLS-1$ //$NON-NLS-2$ private static final String CREATE_TABLE_CYCLES = "create table cycles (_id integer primary key autoincrement, " //$NON-NLS-1$ +CyclesDBAdapter.NAME+" TEXT," //$NON-NLS-1$ +CyclesDBAdapter.MODEL+" TEXT," //$NON-NLS-1$ +CyclesDBAdapter.YEAR+" TEXT"+ ");"; //$NON-NLS-1$ //$NON-NLS-2$ private final Context context; private DatabaseHelper DBHelper; private SQLiteDatabase db; /** * Constructor * @param ctx */ public DBAdapter(Context ctx) { this.context = ctx; this.DBHelper = new DatabaseHelper(this.context); } private static class DatabaseHelper extends SQLiteOpenHelper { DatabaseHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL(CREATE_TABLE_CARS); db.execSQL(CREATE_TABLE_BOATS); db.execSQL(CREATE_TABLE_CYCLES); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // Adding any table mods to this guy here } } /** * open the db * @return this * @throws SQLException * return type: DBAdapter */ public DBAdapter open() throws SQLException { this.db = this.DBHelper.getWritableDatabase(); return this; } /** * close the db * return type: void */ public void close() { this.DBHelper.close(); } } </code></pre> <p>The DBAdapter class only gets called when the app first starts and its only responsibility is to create/upgrade the tables. All other access to the data is done through the individual "adapter" class. I've found that this works perfectly and does not create the versioning issues that I mentioned earlier.</p> <p>Hope this helps.</p>

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