Android數據存儲SQLite的事務操做

          使用SQLiteDatabase的beginTransaction()方法能夠開啓一個事務，程序執行到endTransaction() 方法時會檢查事務的標誌是否爲成功，若是程序執行到endTransaction()以前調用了setTransactionSuccessful() 方法設置事務的標誌爲成功則提交事務，若是沒有調用setTransactionSuccessful() 方法則回滾事務。

        下面是一個例子：

/**

 * 保存連載更新的最大章節數

 *

 * @param bookId

 * @param bookChapterTotalNum

 */

public void saveBookChapterTotalNum(String bookId, int bookChapterTotalNum) {

 synchronized (MyOpenHelper.databaseLock) {

  SQLiteDatabase db = null;

  try {

   UserInfo userInfo = UserManager.INSTANCE.getUserInfo();

   String username = userInfo.getUsername();

   if (username == null || "".equals(username)) {

    username = MyOpenHelper.AdminUser;

   }

   db = MyOpenHelper.getInstance().getWritableDatabase();

   db.beginTransaction();

   try {

    if (isHave(db, bookId, username)) {

     String sql = "UPDATE "

       + tableName

       + " SET bookChapterTotalNum=? WHERE bookId=? and (username=? or username='"

       + MyOpenHelper.AdminUser + "')";

     Object[] bindArgs = { bookChapterTotalNum, bookId,

       username };

     db.execSQL(sql, bindArgs);

    }

    db.setTransactionSuccessful();

   } catch (Exception e) {

    e.printStackTrace();

   } finally {

    db.endTransaction();

   }

  } catch (Exception e) {

   e.printStackTrace();

  } finally {

   closeDB(db);

  }

 }

}