问SqliteOpenHelper类的getReadbleDataBase()中出现异常

EN

   10-08 11:34:24.163: E/SQLiteOpenHelper(18710): Couldn't open quytech.db for writing (will try read-only):
10-08 11:34:24.163: E/SQLiteOpenHelper(18710): android.database.sqlite.SQLiteException: Can't downgrade database from version 6 to 1
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at android.database.sqlite.SQLiteOpenHelper.onDowngrade(SQLiteOpenHelper.java:325)
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:186)
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:249)
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at com.quytech.androidclient.data.MessageCountProvider.query(MessageCountProvider.java:156)
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at android.content.ContentProvider$Transport.query(ContentProvider.java:189)
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at android.content.ContentResolver.query(ContentResolver.java:315)
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at com.quytech.androidclient.service.SmackableImp$6.processPacket(SmackableImp.java:1781)
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at org.jivesoftware.smack.Connection$ListenerWrapper.notifyListener(Connection.java:829)
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at org.jivesoftware.smack.PacketReader$ListenerNotification.run(PacketReader.java:463)
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:442)
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at java.util.concurrent.FutureTask.run(FutureTask.java:137)
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
10-08 11:34:24.163: E/SQLiteOpenHelper(18710):  at java.lang.Thread.run(Thread.java:864)

Cursor cursor = mContentResolver.query(MessageCountProvider.CONTENT_URI,
                        null,  MessageCountConstant.JID + " = ? AND "
                        + MessageCountConstant.To_USER + " = ? AND " 
                        + MessageCountConstant.DATE + " = ? ", new String [] {mConfig.userName,toJID,date},null);


                if(cursor.getCount() > 0)
                {
                    cursor.moveToFirst();
                    int recieveMessageCountColmnIndex = cursor.getColumnIndexOrThrow(MessageCountConstant.RECIEVE_MESSAGE_COUNT);
                    int sendMessageCountColmnIndex = cursor.getColumnIndexOrThrow(MessageCountConstant.SEND_MESSAGE_COUNT);
                    int dateColumnIndex = cursor.getColumnIndexOrThrow(MessageCountConstant.DATE);
                    String dateDB = cursor.getString(dateColumnIndex);
                    int sendMessageCount = cursor.getInt(sendMessageCountColmnIndex);
                    int reciveMessageCount = cursor.getInt(recieveMessageCountColmnIndex);

                    updateMessageCountInDB(mConfig.userName, toJID, sendMessageCount+1, reciveMessageCount, date);
                }
                else
                {
                    addMessageCountInDB(mConfig.userName, toJID, 1, 0, date);

                }

@Override
public Cursor query(Uri url, String[] projectionIn, String selection,
        String[] selectionArgs, String sortOrder) {
    // TODO Auto-generated method stub
    SQLiteQueryBuilder qBuilder = new SQLiteQueryBuilder();
    int match = URI_MATCHER.match(url);

    switch (match) {
    case MESSAGES:
        qBuilder.setTables(TABLE_NAME);
        break;
    case MESSAGE_ID:
        qBuilder.setTables(TABLE_NAME);
        qBuilder.appendWhere("_id=");
        qBuilder.appendWhere(url.getPathSegments().get(1));
        break;
    default:
        throw new IllegalArgumentException("Unknown URL " + url);
    }

    String orderBy;
    if (TextUtils.isEmpty(sortOrder)) {
        orderBy = ChatConstants.DEFAULT_SORT_ORDER;
    } else {
        orderBy = sortOrder;
    }

    SQLiteDatabase db = mOpenHelper.getReadableDatabase();
    Cursor ret = qBuilder.query(db, projectionIn, selection, selectionArgs,
            null, null, orderBy);

    if (ret == null) {
        infoLog("MessageCountProvider.query: failed");
    } else {
        ret.setNotificationUri(getContext().getContentResolver(), url);
    }

    return ret;
}







private static class MessageCountDataBaseHelper extends SQLiteOpenHelper {

private static final String DATABASE_NAME = "quytech.db";
private static final int DATABASE_VERSION = 1;

public MessageCountDataBaseHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) 
{
    if (LogConstants.LOG_DEBUG) {
        infoLog("creating new chat table");
    }

    db.execSQL("CREATE TABLE " + TABLE_NAME + " (" 

            + MessageCountConstant._ID+ " INTEGER PRIMARY KEY AUTOINCREMENT,"
            + MessageCountConstant.JID + " TEXT," 
            + MessageCountConstant.To_USER + " TEXT,"
            + MessageCountConstant.SEND_MESSAGE_COUNT + " INTEGER,"
            + MessageCountConstant.RECIEVE_MESSAGE_COUNT + " INTEGER,"
            + MessageCountConstant.DATE + " DATE"

            +");"

            );
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    infoLog("onUpgrade: from " + oldVersion + " to " + newVersion);

    infoLog("onUpgrade: from " + oldVersion + " to " + newVersion);
    switch (oldVersion) {
    default:
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
        onCreate(db);
    }
}
}