Android 无法从复制的数据库中查询表

我有一个字典应用程序的大型数据库。 我将该数据库从原始文件夹复制到应用程序包的数据库路径

public class DbHelper extends SQLiteOpenHelper {


       private SQLiteDatabase mDataBase;
      private static int DB_VERSION = 1;

      private Context mContext;

    private static String DB_PATH;

    private static final String DATABASE_NAME = "offlinedictionary.db";

    private static final String LOG_TAG = "DBHelper";


    public DbHelper(@Nullable Context context) {
        super(context, DATABASE_NAME, null, DB_VERSION);
        Log.d(LOG_TAG,"DbHelper constructor");
        mContext = context;

        if (android.os.Build.VERSION.SDK_INT >= 4.2) {
            DB_PATH = context.getApplicationInfo().dataDir + "/databases/";


        } else {
            DB_PATH = "/data/data/" + context.getPackageName() + "/databases/";
        }
        Log.d(LOG_TAG,"database path: "+DB_PATH);
    }

    public void createDataBase() throws IOException {

        // If database not exists copy it from the assets

        boolean mDataBaseExist = checkDataBase();
        Log.d(LOG_TAG,"createDataBase: mDataBaseExist "+mDataBaseExist);

        if (mDataBaseExist) {
            //  this.getReadableDatabase();
            // this.close();
            try {
                // Copy the database from assests
                copyDataBase();
                Log.e("DataBaseHelper", "createDatabase database created");
            } catch (IOException mIOException) {
                throw new Error("Error Copying DataBase");
            }
        }

    }

    private boolean checkDataBase() {
        File dbFile = new File(DB_PATH + DATABASE_NAME);
        //Log.v("dbFile", dbFile + "   "+ dbFile.exists());

        Log.d(LOG_TAG,"checkDataBase: dbFile "+dbFile.getName());
        Log.d(LOG_TAG,"checkDataBase: dbFile.exists() "+dbFile.exists());
        return dbFile.exists();
    }

    private void copyDataBase() throws IOException {


        InputStream mInput = mContext.getResources().openRawResource(R.raw.offlinedictionary);
        String outFileName = DB_PATH + DATABASE_NAME;
        OutputStream mOutput = new FileOutputStream(outFileName);
        Log.d(LOG_TAG,"copyDataBase: mInput "+mInput);
        Log.d(LOG_TAG,"copyDataBase: outFileName "+outFileName);
        Log.d(LOG_TAG,"copyDataBase: mOutput "+mOutput);
        byte[] mBuffer = new byte[1024];
        int mLength;
        while ((mLength = mInput.read(mBuffer)) > 0) {
            mOutput.write(mBuffer, 0, mLength);
            Log.d(LOG_TAG,"copyDataBase: mLength "+mLength);
        }
        Log.d(LOG_TAG,"copyDataBase: done ");
        mOutput.flush();
        mOutput.close();
        mInput.close();

    }

    @Override
    public void onCreate(SQLiteDatabase db) {


        try {
            createDataBase();
        } catch (IOException e) {
            e.printStackTrace();
        }
     }
  }

上面的代码成功地将MyDB从原始文件夹复制到数据库路径

该数据库包含表“worddictionary”

但是当我查询这个表时，我得到一个错误，说没有这样的表存在。但我在复制的数据库中看到了表及其内容

public class LoadActivity extends AppCompatActivity {

    private static final String LOG_TAG = "LoadActivity";

    private DbHelper dbHelper;
    private SQLiteDatabase mDatabase;

    private Context mContext;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_load);

        Log.d(LOG_TAG,"Starting Load Activity");

        mContext = getApplicationContext();

        dbHelper = new DbHelper(this);
        mDatabase = dbHelper.getWritableDatabase();

   

        Log.d(LOG_TAG,"Call insertData");
        insertData();


    }


    public void insertData(){
        Log.d(LOG_TAG,"insertData");

        InsertData fetchWordDetails = new InsertData();
        fetchWordDetails.execute();

    }
    
    private class InsertData extends AsyncTask<Void,Void,Void> {
    
    
    }
    
     @Override
     protected Void doInBackground(Void... voids) {
        
        
            String wordQuery = "SELECT * FROM worddictionary;";
            Cursor wordCursor = mDatabase.rawQuery(wordQuery,null);
            int wordCount = wordCursor.getCount();
            Log.d(LOG_TAG,"wod wordCount: "+wordCount);
        
    }
    
}

公共类LoadActivity扩展了AppCompative活动{
私有静态最终字符串日志\u TAG=“LoadActivity”；
私人DbHelper DbHelper；
私有SQLITE数据库mDatabase；
私有上下文；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_load）；
Log.d（Log_标签，“启动负载活动”）；
mContext=getApplicationContext（）；
dbHelper=新的dbHelper（this）；
mDatabase=dbHelper.getWritableDatabase（）；
Log.d（Log_标签，“callinsertdata”）；
insertData（）；
}
公共void insertData（）{
Log.d（Log_标签，“insertData”）；
InsertData fetchWordDetails=新建InsertData（）；
fetchWordDetails.execute（）；
}
私有类InsertData扩展异步任务{
}
@凌驾
受保护的空位背景（空位…空位）{
String wordQuery=“从worddictionary中选择*”；
Cursor-wordCursor=mDatabase.rawQuery（wordQuery，null）；
int wordCount=wordCursor.getCount（）；
Log.d（Log_标签，“wod wordCount:”+wordCount）；
}
}

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有人能解释出哪里出了问题吗？

你不是在抄袭<代码>//如果数据库不存在，复制它…好吧，你这么说。但请再次查看您的代码。只有当数据库确实存在时，您才能复制。@blackapps当应用程序启动时，数据库被创建，当数据库存在时，我故意复制数据库，并且数据库被复制，我已从设备文件资源管理器下载了数据库，并检查了我的数据是否存在，但无法查询这些数据