public static final String KEY_TITLE = "title";    //鏁版嵁琛ㄥ瓧娈?/span>

    public static final String KEY_BODY = "body";    //鏁版嵁琛ㄥ瓧娈?/span>

    public static final String KEY_ROWID = "_id";    //鏁版嵁琛ㄥ瓧娈?/span>

    private DatabaseHelper mDbHelper;    //SQLiteOpenHelper瀹炰緥瀵硅薄

    private SQLiteDatabase mDb;    //鏁版嵁搴撳疄渚嬪璞?/span>

    //鏁版嵁琛ㄥ垱寤鸿鍙?/span>

    private static final String DATABASE_CREATE  = "create table notes (_id integer primary key autoincrement, "

                    + "title text not null, body text not null);";

    private static final String DATABASE_NAME = "data";    //鏁版嵁搴撳悕

    private static final String DATABASE_TABLE = "notes";    //鏁版嵁搴撹〃鍚?/span>

    private static final int DATABASE_VERSION = 2;    //鏁版嵁搴撶増鏈彿

    private final Context mCtx;    //涓婁笅鏂囧疄渚?/span>

    private static class DatabaseHelper extends SQLiteOpenHelper {    //鏁版嵁搴撹緟鍔╃被

        DatabaseHelper(Context context) {

            super(context, DATABASE_NAME, null, DATABASE_VERSION);

        }

        @Override

        public void onCreate(SQLiteDatabase db) {

            db.execSQL(DATABASE_CREATE);

        }

        @Override

        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

            db.execSQL("DROP TABLE IF EXISTS notes");

            onCreate(db);

        }

    }

    /**

     * Constructor - takes the context to allow the database to be opened/created

     * 

     * @param ctx the Context within which to work

     */

    public MyDbHelper(Context ctx) {

        this.mCtx = ctx;

    }

    /**

     * Open the notes 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 MyDbHelper open() throws SQLException {

        mDbHelper = new DatabaseHelper(mCtx);

        mDb = mDbHelper.getWritableDatabase();

        return this;

    }

    public void close() {

        mDbHelper.close();

    }

    /**

     * Create a new note using the title and body provided. If the note is successfully created 

* return the new rowId for that note, otherwise return a -1 to indicate failure.

     * 

     * @param title the title of the note

     * @param body the body of the note

     * @return rowId or -1 if failed

     */

    public long createNote(String title, String body) {

        ContentValues initialValues = new ContentValues();

        initialValues.put(KEY_TITLE, title);

        initialValues.put(KEY_BODY, body);

        return mDb.insert(DATABASE_TABLE, null, initialValues);

    }

    /**

     * Delete the note with the given rowId

     * 

     * @param rowId id of note to delete

     * @return true if deleted, false otherwise

     */

    public boolean deleteNote(long rowId) {

        return mDb.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;

    }

    /**

     * Return a Cursor over the list of all notes in the database

     * 

     * @return Cursor over all notes

     */

    public Cursor fetchAllNotes() {

        return mDb.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_TITLE,KEY_BODY}, null, null, null, null, null);

    }

    /**

     * Return a Cursor positioned at the note that matches the given rowId

     * 

     * @param rowId id of note to retrieve

     * @return Cursor positioned to matching note, if found

     * @throws SQLException if note could not be found/retrieved

     */

    public Cursor fetchNote(long rowId) throws SQLException {

        Cursor mCursor = mDb.query(true, DATABASE_TABLE, new String[] {KEY_ROWID,KEY_TITLE, 

KEY_BODY}, KEY_ROWID + "=" + rowId, null, null, null, null, null);

        if (mCursor != null) {

            mCursor.moveToFirst();

        }

        return mCursor;

    }

    /**

     * Update the note using the details provided. The note to be updated is specified using the rowId, 

*and it is altered to use the title and body values passed in

     * 

     * @param rowId id of note to update

     * @param title value to set note title to

     * @param body value to set note body to

     * @return true if the note was successfully updated, false otherwise

     */

    public boolean updateNote(long rowId, String title, String body) {

        ContentValues args = new ContentValues();

        args.put(KEY_TITLE, title);

        args.put(KEY_BODY, body);

        return mDb.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;

    }

}

杞嚜锛?a href="http://www.cnblogs.com/jerrychoi/archive/2010/04/15/1712704.html">http://www.cnblogs.com/jerrychoi/archive/2010/04/15/1712704.html