SQLite Ошибка базы данных: Нет такой стол

Question

Я использовал DataBaseHelper класс, чтобы скопировать файл в SQLite базы данных из папки assets, но когда я запускаю этот код:

DataBaseHelper dbhelper=new DataBaseHelper(this); 
SQLiteDatabase db=dbhelper.getReadableDatabase(); 
Cursor cur=db.rawQuery("SELECT * FROM data", null); 

Я получаю эту ошибку: android.database.sqlite.SQLiteException: no such table: data
Но Я уверен, что эта таблица существует ...

класс код:

class DataBaseHelper extends SQLiteOpenHelper { 

    private static String DB_PATH = "/data/data/com.example.amin.rendertest/databases/"; 
    private static String DB_NAME = "db.db"; 
    private SQLiteDatabase myDataBase; 
    private final Context myContext; 

    public DataBaseHelper (Context context) { 
     super(context, DB_NAME, null, 1); 
     this.myContext = context; 

    } 

    public void crateDatabase() throws IOException { 
     boolean vtVarMi = isDatabaseExist(); 

     if (!vtVarMi) { 
      this.getReadableDatabase(); 

      try { 
       copyDataBase(); 
      } catch (IOException e) { 
       throw new Error("Error copying database"); 
      } 
     } 
    } 

    private void copyDataBase() throws IOException { 

     // Open your local db as the input stream 
     InputStream myInput = myContext.getAssets().open(DB_NAME); 

     // Path to the just created empty db 
     String outFileName = DB_PATH + DB_NAME; 

     // Open the empty db as the output stream 
     OutputStream myOutput = new FileOutputStream(outFileName); 

     // transfer bytes from the inputfile to the outputfile 
     byte[] buffer = new byte[1024]; 
     int length; 
     while ((length = myInput.read(buffer)) > 0) { 
      myOutput.write(buffer, 0, length); 
     } 

     // Close the streams 
     myOutput.flush(); 
     myOutput.close(); 
     myInput.close(); 
    } 

    private boolean isDatabaseExist() { 
     SQLiteDatabase kontrol = null; 

     try { 
      String myPath = DB_PATH + DB_NAME; 
      kontrol = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY); 

     } catch (SQLiteException e) { 
      kontrol = null; 
     } 

     if (kontrol != null) { 
      kontrol.close(); 
     } 
     return kontrol != null ? true : false; 
    } 

    public void openDataBase() throws SQLException { 

     // Open the database 
     String myPath = DB_PATH + DB_NAME; 
     myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE); 

    } 

    public Cursor Sample_use_of_helper() { 

     return myDataBase.query("TABLE_NAME", null, null, null, null, null, null); 
    } 

    @Override 
    public synchronized void close() { 
     if (myDataBase != null) 
      myDataBase.close(); 
     super.close(); 
    } 

    @Override 
    public void onCreate(SQLiteDatabase db) { 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
    } 
} 

Answer 1

моя проблема решаемая

https://github.com/jgilfelt/android-sqlite-asset-helper

свою работу для меня

Answer 2

Попробуйте этот класс.

public class DataBaseHelper extends SQLiteOpenHelper{ 

    //The Android's default system path of your application database. 
    private static String DB_NAME = "database_db.sqlite"; 
    private static String DB_PATH = ""; 



    private SQLiteDatabase myDataBase; 

    private final Context myContext; 

    /** 
    * Constructor 
    * Takes and keeps a reference of the passed context in order to access to the application assets and resources. 
    * @param context 
    */ 
    public DataBaseHelper(Context context) { 

     super(context, DB_NAME, null, 1); 
     this.myContext = context; 
     if (android.os.Build.VERSION.SDK_INT >= 17) 
      DB_PATH = context.getApplicationInfo().dataDir + "/databases/"; 
     else 
      DB_PATH = "/data/data/" + context.getPackageName() + "/databases/"; 
     Log.d("path", DB_PATH); 
    } 

    /** 
    * Creates a empty database on the system and rewrites it with your own database. 
    * */ 
    public void createDataBase() throws IOException{ 

     boolean dbExist = checkDataBase(); 

     if(dbExist){ 
      //do nothing - database already exist 
     }else{ 

      //By calling this method and empty database will be created into the default system path 
       //of your application so we are gonna be able to overwrite that database with our database. 
      this.getReadableDatabase(); 

      try { 

       copyDataBase(DB_NAME,DB_NAME); 

      } catch (IOException e) { 

       throw new Error("Error copying database"); 

      } 
     } 

    } 

    /** 
    * Check if the database already exist to avoid re-copying the file each time you open the application. 
    * @return true if it exists, false if it doesn't 
    */ 
    private boolean checkDataBase(){ 

     SQLiteDatabase checkDB = null; 

     try{ 
      String myPath = DB_PATH + DB_NAME; 
      checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY); 

     }catch(SQLiteException e){ 

      //database does't exist yet. 

     } 

     if(checkDB != null){ 

      checkDB.close(); 

     } 

     return checkDB != null ? true : false; 
    } 

    /** 
    * Copies your database from your local assets-folder to the just created empty database in the 
    * system folder, from where it can be accessed and handled. 
    * This is done by transfering bytestream. 
    * */ 
    private void copyDataBase(String assest , String db) throws IOException{ 

     //Open your local db as the input stream 
     InputStream myInput = myContext.getAssets().open(assest); 
     // Path to the just created empty db 
     String outFileName = DB_PATH + db; 

     //Open the empty db as the output stream 
     OutputStream myOutput = new FileOutputStream(outFileName); 

     //transfer bytes from the inputfile to the outputfile 
     byte[] buffer = new byte[1024]; 
     int length; 
     while ((length = myInput.read(buffer))>0){ 
      myOutput.write(buffer, 0, length); 
     } 

     //Close the streams 
     myOutput.flush(); 
     myOutput.close(); 
     myInput.close(); 

    } 

    public void openDataBase() throws SQLException{ 

     try { 
      createDataBase(); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 
     //Open the database 
     String myPath = DB_PATH + DB_NAME; 
     myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY); 

    } 

    @Override 
    public synchronized void close() { 

      if(myDataBase != null) 
       myDataBase.close(); 

      super.close(); 

    } 

    @Override 
    public void onCreate(SQLiteDatabase db) { 

    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 

    } 

Счастливый кодирования ..