当表不为空时，cursor.getCount（）返回0

Question

我在SQLite中有一个只包含一个条目的表 - 我的数据库的版本号。 目前正在使用DB Browser for SQLite我可以看到该表有一行。

但是当我运行以下代码时，它显示cursor.getCount（）为0 WHY ??

private boolean checkVersion(DBmanipulation currentDB) {
    //returning value
    boolean newerVersionExist = false;

    //Get SQLiteVersion
    String currentQuery = "SELECT " + KEY_VERSION + " FROM " + TABLE_VERSION;
    Cursor cursor = getReadableDatabase().rawQuery(currentQuery, null);

    if (cursor != null && cursor.getCount() > 0) {
        cursor.moveToFirst();

        //there is something in the table
        //Check if the current version is older
        int currentVersion = cursor.getInt(cursor.getColumnIndex("version_number"));
        System.out.println("RESULTzz Current version is:" + currentVersion);

        int remoteVersion = currentDB.getVersionNumber();
        System.out.println("RESULTzz Remote version is:" + remoteVersion);

        if (remoteVersion > currentVersion) {
            newerVersionExist = true;
        }
        return newerVersionExist;
    }