sqlite курсор, возвращающий неправильное значение для столбца

Question

Почему я беру из базы данных null из колонки url?

Я добавляю данные в SQLite как этот

void addObjects(Objects object) { 
     SQLiteDatabase db = this.getWritableDatabase(); 

     ContentValues values = new ContentValues(); 

     values.put(OBJECT_ID,"10"); // OBJECT Name 
     values.put(OBJECT_NAME, "H"); // OBJECT Name 
     values.put(OBJECT_URL, "http://api.androidhive.info/images/sample.jpg"); // OBJECT URL 
     values.put(OBJECT_TYPE, "image"); // Contact type 
     System.out.println(values); 

     // Inserting Row 
     db.insert(TABLE_OBJECTS, null, values); 
     db.close(); // Closing database connection 
    } 

в результате регистрации значений www.i I/System.out﹕ TYPE=image NAME=H ID=10 URL=http://api.androidhive.info/images/sample.jpg

однако, когда я получаю все результат я имею URL = нуль

public List<Objects> getAllObjects() { 
    List<Objects> Objectslist = new ArrayList<Objects>(); 
    // Select All Query 
    String selectQuery = "SELECT * FROM " + TABLE_OBJECTS; 

    SQLiteDatabase db = this.getWritableDatabase(); 
    Cursor cursor = db.rawQuery(selectQuery, null); 

    // looping through all rows and adding to list 
    if (cursor.moveToFirst()) { 
     do { 
      Objects object = new Objects(); 
      Log.d("OBJECT_URL", OBJECT_URL); 

      object.setId(cursor.getInt(cursor.getColumnIndex(OBJECT_ID))); 
      object.setName(cursor.getString(cursor.getColumnIndex(OBJECT_NAME))); 
      object.setUrl(cursor.getString(cursor.getColumnIndex(OBJECT_URL))); 
      // Adding contact to list 
      Objectslist.add(object); 
     } while (cursor.moveToNext()); 
    } 

Это Основная деятельность Я получаю результат sqlite

List<Objects> Objects = db.getAllObjects(); 
    Log.d("he","tttttt"); 
    System.out.println(Objects); 
    DBadapter adapter = new DBadapter(getApplicationContext(), R.layout.grid_item_layout, Objects); 

это результат системы outprint

[Objects{id=10, name='http://api.androidhive.info/images/sample.jpg', url='null', type='null', category='null'}, Objects{id=10, name='http://api.androidhive.info/images/sample.jpg', url='null', type='null', category='null'} 

это полный класс SQLite

 public class DatabaseHandler extends SQLiteOpenHelper { 

// All Static variables 
// Database Version 
private static final int DATABASE_VERSION = 1; 



    // Contacts table name 
    private static final String TABLE_OBJECTS = "OBJECTS"; 
    private static final String OBJECT_ID="ID"; 
    private static final String OBJECT_NAME="NAME"; 
    private static final String OBJECT_TYPE ="TYPE"; 
    private static final String OBJECT_URL ="URL"; 
    private static final String OBJECT_CATEGORY ="CATEGORY"; 
    private static final String OBJECT_DATE_ADDED ="DATE_ADDED"; 
    private static final String OBJECT_USERS_ID ="USERS_ID"; 
    private static final String OBJECT_HIDE_YN ="HIDE_YN"; 


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

    // Creating Tables 
    @Override 
    public void onCreate(SQLiteDatabase db){ 
     db.execSQL("DROP TABLE IF EXISTS " + TABLE_OBJECTS); 

     String CREATE_OBJECTS_TABLE ="CREATE TABLE " +TABLE_OBJECTS+"(" 
     + OBJECT_ID +" INTEGER PRIMARY KEY AUTOINCREMENT," 
     + OBJECT_NAME +" VARCHAR(100) NULL," 
     + OBJECT_TYPE +" VARCHAR(10) NULL," 
     + OBJECT_URL +" VARCHAR(1000) NULL," 
     +OBJECT_CATEGORY +" VARCHAR(50) NULL," 
     +OBJECT_DATE_ADDED +" DATETIME NULL," 
     +OBJECT_USERS_ID +" NUMERIC(10) NULL," 
     +OBJECT_HIDE_YN +" VARCHAR(1) NULL) "; 
     db.execSQL(CREATE_OBJECTS_TABLE); 
    } 
    // Upgrading database 
    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     // Drop older table if existed 
     db.execSQL("DROP TABLE IF EXISTS " + TABLE_OBJECTS); 

     // Create tables again 
     onCreate(db); 
    } 

    /** 
    * All CRUD(Create, Read, Update, Delete) Operations 
    */ 

    // Adding new contact 
    void addObjects(Objects object) { 
     SQLiteDatabase db = this.getWritableDatabase(); 

     ContentValues values = new ContentValues(); 

     values.put(OBJECT_ID,"10"); // OBJECT Name 
     values.put(OBJECT_NAME, "H"); // OBJECT Name 
     values.put(OBJECT_URL, "http://api.androidhive.info/images/sample.jpg"); // OBJECT URL 
     values.put(OBJECT_TYPE, "image"); // Contact type 
     System.out.println(values); 

     // Inserting Row 
     long id = db.insert(TABLE_OBJECTS, null, values); 
     System.out.println("id:"+id); 
     db.insert(TABLE_OBJECTS, null, values); 
     db.close(); // Closing database connection 
    } 
    // Objects object=new Objects(String); 

    // Getting single contact 
    Objects geturl(String name) { 
     SQLiteDatabase db = this.getReadableDatabase(); 
     Cursor cursor = db.query(TABLE_OBJECTS, new String[] {OBJECT_URL, 
         OBJECT_NAME , OBJECT_CATEGORY, OBJECT_TYPE }, OBJECT_NAME + "=?", 
       new String[] { String.valueOf(name) }, null, null, null, null); 
     if (cursor != null) 
      cursor.moveToFirst(); 

     Objects object = new Objects(cursor.getString(0),cursor.getString(1), 
       cursor.getString(2),cursor.getString(3)); 

     return object; 
    } 

    // Getting All Contacts 
    public List<Objects> getAllObjects() { 
     List<Objects> Objectslist = new ArrayList<Objects>(); 
     // Select All Query 
     String selectQuery = "SELECT * FROM " + TABLE_OBJECTS; 

     SQLiteDatabase db = this.getWritableDatabase(); 
     Cursor cursor = db.rawQuery(selectQuery, null); 

     // looping through all rows and adding to list 
     if (cursor.moveToFirst()) { 
      do { 
       Objects object = new Objects(); 
       Log.d("OBJECT_URL", OBJECT_URL); 

       object.setId(cursor.getInt(cursor.getColumnIndex(OBJECT_ID))); 
       object.setName(cursor.getString(cursor.getColumnIndex(OBJECT_NAME))); 
       object.setUrl(cursor.getString(cursor.getColumnIndex(OBJECT_URL))); 
       // Adding contact to list 
       Objectslist.add(object); 
      } while (cursor.moveToNext()); 
     } 

     // return contact list 
     return Objectslist; 
    } 

    // Updating single contact 
    public int updateContact(Objects object) { 
     SQLiteDatabase db = this.getWritableDatabase(); 

     ContentValues values = new ContentValues(); 
     values.put(OBJECT_NAME, object.getName()); // OBJECT Name 
     values.put(OBJECT_URL, object.getUrl()); // OBJECT URL 
     values.put(OBJECT_TYPE, object.getType()); // Contact type 
     values.put(OBJECT_CATEGORY, object.getCategory()); // Contact category 

     // updating row 
     return db.update(TABLE_OBJECTS, values, OBJECT_ID + " = ?", 
       new String[] { String.valueOf(object.getId()) }); 
    } 

    // Deleting single contact 
    public void deleteContact(Objects objects) { 
     SQLiteDatabase db = this.getWritableDatabase(); 
     db.delete(TABLE_OBJECTS, OBJECT_ID + " = ?", 
       new String[] { String.valueOf(objects.getId()) }); 
     db.close(); 
    } 


    // Getting contacts Count 
    public int getObjectsCount() { 
     String countQuery = "SELECT * FROM " + TABLE_OBJECTS; 
     SQLiteDatabase db = this.getReadableDatabase(); 
     Cursor cursor = db.rawQuery(countQuery, null); 
     cursor.close(); 

     // return count 
     return cursor.getCount(); 
    } 

} 

Answer 1

В вашем методе Objects geturl(String name) измените

Cursor cursor = db.query(TABLE_OBJECTS, new String[] {OBJECT_URL, 
       OBJECT_NAME , OBJECT_CATEGORY, OBJECT_TYPE }, OBJECT_NAME + "=?", 
       new String[] { String.valueOf(name) }, null, null, null, null); 

в

Cursor cursor = db.query(TABLE_OBJECTS, new String[] {OBJECT_ID, 
       OBJECT_NAME , OBJECT_URL, OBJECT_TYPE }, OBJECT_NAME + "=?", 
       new String[] { String.valueOf(name) }, null, null, null, null); 

Предположив, что ваши объектов класса имеет следующую структуру:

public class Objects { 
    private String id; 
    private String name; 
    private String url; 
    private String type; 

    // methods 
} 

tableColumns аргумента (new String[] {OBJECT_ID,OBJECT_NAME , OBJECT_URL, OBJECT_TYPE }), передаваемая методу db.query() должен соблюдать тот же порядок, что и в классе Objects (сначала id , 2nd name, 3rd url, 4th type)