android.database.sqlite.SQLiteConstraintException: UNIQUE constraint failed

存在2条预警信息时, 调用addToAlarms()向数据库插入数据, 但第二次插入数据时, 报exception, 插入数据失败.

    public void addToAlarms(String area_weather_id, WeatherAlarm alarm) {
        mDB.beginTransaction();
        try {
            ContentValues cv = new ContentValues();
            cv.put(WeatherDBOpenHelper.AREA_WEATHER_ID, area_weather_id);
            cv.put(WeatherDBOpenHelper.ALARMS_AREA_NAME, alarm.getAreaName());
            cv.put(WeatherDBOpenHelper.ALARMS_AREA_LAST_ACTION, alarm.getAreaLastAction());
            cv.put(WeatherDBOpenHelper.ALARMS_AREA_TEXT, alarm.getAreaText());
            cv.put(WeatherDBOpenHelper.ALARMS_BEGIN_TIME, alarm.getBeginTime());
            cv.put(WeatherDBOpenHelper.ALARMS_END_TIME, alarm.getEndTime());
            cv.put(WeatherDBOpenHelper.ALARMS_COLOR, alarm.getColor());
            cv.put(WeatherDBOpenHelper.ALARMS_DESCRIPTION, alarm.getDescription());
            cv.put(WeatherDBOpenHelper.ALARMS_SOURCE, alarm.getSource());
            cv.put(WeatherDBOpenHelper.ALARMS_CATEGORY, alarm.getCategory());
            cv.put(WeatherDBOpenHelper.ALARMS_TYPE, alarm.getType());
            cv.put(WeatherDBOpenHelper.ALARMS_INDEX, alarm.getTypeIndex());
            cv.put(WeatherDBOpenHelper.ALARMS_MOBILELINK, alarm.getMobileLink());

            mDB.insert(WeatherDBOpenHelper.TABLE_ALARMS, null, cv);
            mDB.setTransactionSuccessful();
        } finally {
            mDB.endTransaction();
        }
    }

第一次插入正确，当第二次插入时相当于再次插入同样的信息，由于id已存在，所以抛出了异常.
原因是, 创建table时, 把AREA_WEATHER_ID作为主键声明导致的.

        db.execSQL("create table " + TABLE_ALARMS + "(" + AREA_WEATHER_ID + " text primary key , "
                + ALARMS_AREA_NAME + " text , " + ALARMS_AREA_LAST_ACTION + " text , "
                + ALARMS_AREA_TEXT + " text , " + ALARMS_BEGIN_TIME + " text , "
                + ALARMS_END_TIME + " text , " + ALARMS_COLOR + " text , "
                + ALARMS_DESCRIPTION + " text , " + ALARMS_SOURCE + " text , "
                + ALARMS_CATEGORY + " text , " + ALARMS_TYPE + " text , "
                + ALARMS_INDEX + " text , "
                + ALARMS_MOBILELINK + " text)");

改成这样就解决了.

        db.execSQL("create table " + TABLE_ALARMS + "(" + AREA_WEATHER_ID + " text , "
                + ALARMS_AREA_NAME + " text , " + ALARMS_AREA_LAST_ACTION + " text , "
                + ALARMS_AREA_TEXT + " text , " + ALARMS_BEGIN_TIME + " text , "
                + ALARMS_END_TIME + " text , " + ALARMS_COLOR + " text , "
                + ALARMS_DESCRIPTION + " text , " + ALARMS_SOURCE + " text , "
                + ALARMS_CATEGORY + " text , " + ALARMS_TYPE + " text , "
                + ALARMS_INDEX + " text , "
                + ALARMS_MOBILELINK + " text)");

refer to:
http://blog.sina.com.cn/s/blog_6182981401018z9u.html