SQLiteOpenHelper的使用范例

public class DBHelper extends SQLiteOpenHelper {
	private static final String DB_NAME = "coll.db";
	private static final String TBL_NAME = "CollTbl";
	private static final String CREATE_TBL = " create table "
			+ " CollTbl(_id integer primary key autoincrement,name text,url text, desc text) ";
	
	private SQLiteDatabase db;

	DBHelper(Context c) {
		super(c, DB_NAME, null, 2);
	}

	@Override
	public void onCreate(SQLiteDatabase db) {
		this.db = db;
		db.execSQL(CREATE_TBL);
	}

	public void insert(ContentValues values) {
		SQLiteDatabase db = getWritableDatabase();
		db.insert(TBL_NAME, null, values);
		db.close();
	}

	public Cursor query() {
		SQLiteDatabase db = getWritableDatabase();
		Cursor c = db.query(TBL_NAME, null, null, null, null, null, null);
		return c;
	}

	public void del(int id) {
		if (db == null)
			db = getWritableDatabase();
		db.delete(TBL_NAME, "_id=?", new String[] { String.valueOf(id) });
	}

	public void close() {
		if (db != null)
			db.close();
	}

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

	}
}

String name = et1.getText().toString();
				String url = et2.getText().toString();
				String desc = et3.getText().toString();

				ContentValues values = new ContentValues();

				values.put("name", name);
				values.put("url", url);
				values.put("desc", desc);

				DBHelper helper = new DBHelper(getApplicationContext());
				helper.insert(values);
				Intent intent = new Intent(AddActivity.this,
						QueryActivity.class);
				startActivity(intent);

public class QueryActivity extends ListActivity {
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		this.setTitle("浏览收藏信息");
		final DBHelper helpter = new DBHelper(this);
		Cursor c = helpter.query();

		String[] from = { "_id", "name", "url", "desc" };
		int[] to = { R.id.text0, R.id.text1, R.id.text2, R.id.text3 };

		SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,
				R.layout.row, c, from, to);
		ListView listView = getListView();
		listView.setAdapter(adapter);
		
		
		final AlertDialog.Builder builder = new AlertDialog.Builder(this);

		listView.setOnItemClickListener(new OnItemClickListener() {
			@Override
			public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
					long arg3) {
				final long temp = arg3;
				builder.setMessage("真的要删除该记录吗？").setPositiveButton("是",
						new DialogInterface.OnClickListener() {
							public void onClick(DialogInterface dialog,
									int which) {
								helpter.del((int)temp);
								Cursor c = helpter.query();
								String[] from = { "_id", "name", "url", "desc" };
								int[] to = { R.id.text0, R.id.text1, R.id.text2, R.id.text3 };

								SimpleCursorAdapter adapter = new SimpleCursorAdapter(getApplicationContext(),
										R.layout.row, c, from, to);
								ListView listView = getListView();
								listView.setAdapter(adapter);
							}
						}).setNegativeButton("否",
						new DialogInterface.OnClickListener() {
							public void onClick(DialogInterface dialog,
									int which) {
								
							}
						});
				AlertDialog ad = builder.create();
				ad.show();
			}
		});
		helpter.close();
	}
}