sqlite数据库：现有表中不存在表

Question

我创建了一个＆＃34; sqlite＆＃34;数据库使用Java应用程序，我将数据插入到数据库的表中。我也用sqliteStudio检查了它。我将数据库复制到Android应用程序的资产文件夹中以使用它。但是，当我尝试从表格中选择数据时，它给了我一个例外＆＃34;没有这样的表OSOLDB＆＃34;。我按照this answer打开现有数据库，这是我的代码：

 public class DBHelper  extends SQLiteOpenHelper{

    private static final String DBName="OSOL";
    private static final String TABLE_NAME="OSOLDB";
    private static final String PARAGRAPH_ID_COL="ID";
    private static final String PARAGRAPH_COL="PAR";
    private static File     DATABASE_FILE;
    private static boolean InvalidDB=false;
    private static final int VERSION = 1;
    private static DBHelper myHelper;
    private Context context;
    private static String DB_PATH="";
    private SQLiteDatabase DB;


    public DBHelper(Context context) {
        super(context, DBName, null, VERSION);
        // TODO Auto-generated constructor stub

        Log.d("DBHELPER","constructor");
        if(android.os.Build.VERSION.SDK_INT >= 17){
               DB_PATH = context.getApplicationInfo().dataDir + "/databases/";         
            }
            else
            {
               DB_PATH = "/data/data/" + context.getPackageName() + "/databases/";
            }
            this.context = context;


    }



        public void createDataBase() throws IOException
        {
            //If database not exists copy it from the assets

            boolean mDataBaseExist = checkDataBase();
            if(!mDataBaseExist)
            {
                this.getReadableDatabase();
                this.close();
                try 
                {
                    //Copy the database from assests
                    copyDataBase();
                    Log.e("DBHELPER", "createDatabase database created");
                } 
                catch (IOException mIOException) 
                {
                    throw new Error("ErrorCopyingDataBase");
                }
            }
        }


      //Open the database, so we can query it
    public boolean openDataBase() throws SQLException
    {
        String mPath = DB_PATH + DBName;
        DB = SQLiteDatabase.openDatabase(mPath, null, SQLiteDatabase.CREATE_IF_NECESSARY);
        //mDataBase = SQLiteDatabase.openDatabase(mPath, null, SQLiteDatabase.NO_LOCALIZED_COLLATORS);
        return DB != null;
    }

       private boolean checkDataBase()
        {
            File dbFile = new File(DB_PATH + DBName);
            Log.v("learn", dbFile.getName() + "   "+ dbFile.exists());
            return dbFile.exists();
        }
/*
    synchronized static DBHelper getInstance( Context context)
    {
        if(myHelper==null)
        {
            myHelper= new DBHelper(context.getApplicationContext());
        }
        return myHelper;
    }*/
    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        InvalidDB=true;
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        InvalidDB=true;
        //isUpgraded=true;
    }


    @Override
    public synchronized void onOpen(SQLiteDatabase db)
    {
        super.onOpen(db);
        if(!db.isReadOnly())
        {
            DATABASE_FILE = context.getDatabasePath(DBName);
        }

    }
    @Override
    public synchronized void close()
    {
            super.close();
    }
      //Copy the database from assets
    private void copyDataBase() throws IOException
    {
        InputStream mInput = context.getAssets().open(DBName);
        String outFileName = DB_PATH + DBName;
        OutputStream mOutput = new FileOutputStream(outFileName);
        byte[] mBuffer = new byte[1024];
        int mLength;
        while ((mLength = mInput.read(mBuffer))>0)
        {
            mOutput.write(mBuffer, 0, mLength);
        }
        mOutput.flush();
        mOutput.close();
        mInput.close();
    }
}

和此：

public class DataAdapter {


    private final Context context;
    private SQLiteDatabase DB;
    private DBHelper helper;

    public DataAdapter(Context contex)
    {
        this.context=contex;
        helper= new DBHelper(contex);
    }

    public DataAdapter createDatabase() throws SQLiteException, IOException
    {

        helper.createDataBase();
        return this;
    }
     public DataAdapter open() throws SQLException 
        {
            try 
            {
                helper.openDataBase();
                helper.close();
                DB = helper.getReadableDatabase();
                Log.d("adapter","shiiiiiit");

            } 
            catch (SQLException mSQLException) 
            {
                Log.e("dataAdapter", "open >>"+ mSQLException.toString());
                throw mSQLException;
            }
            return this;
        }
       public void close() 
        {
            helper.close();
        }

        public Cursor getTestData()
         {
             try
             {
                 String sql ="SELECT * FROM OSOLDB";

                 Cursor mCur = DB.rawQuery(sql, null);
                 if (mCur!=null)
                 {
                    mCur.moveToNext();
                 }
                 return mCur;
             }
             catch (SQLException mSQLException) 
             {
                 Log.e("dataAdapter", "getTestData >>"+ mSQLException.toString());
                 throw mSQLException;
             }
         }
}

为什么即使表存在，我仍然会获得异常？