Android базы данных выборки запроса

Question

private static final String TAG = "DBAdapter"; 
private static final String DATABASE_NAME = "jobDiagnosis"; 
private static final int DATABASE_VERSION = 2; 
Cursor cursor = null; 
private static final String TABLE_DATA = "create table Job_Saved (" + 
     "Id text not null," + 
     "Title text not null," + 
     "Location text not null," + 
     "State text not null," + 
     "Company text not null," + 
     "Description text not null," + 
     "Status text not null," + 
     "Username text not null," + 
     "Password text not null)"; 
private final Context context; 
private DatabaseHelper dbHelper; 
private SQLiteDatabase db; 
private static DBAdapter instance; 

private DBAdapter(Context c) { 
    System.out.println("Constructor of DB Adapter..."); 
    this.context = c; 
    System.out.println("Creating the object of db helper class.."); 
    try 
    { 
    dbHelper = new DatabaseHelper(context); 
    dbHelper.getWritableDatabase(); 
    } 
    catch (Exception e) { 
     // TODO: handle exception 
     Log.d("err", ""+e); 
    } 
} 

public static DBAdapter getInstance(Context C) { 
    if (null == instance) { 
     instance = new DBAdapter(C); 
    } 
    return instance; 
} 

public void openReadableDatabase() throws SQLException { 
    db = dbHelper.getReadableDatabase(); 
} 

public void openWritableDatabase() throws SQLException { 
    db = dbHelper.getWritableDatabase(); 

} 

public void close() { 
    dbHelper.close(); 
} 
public long DeleteLocation(String name) 
{ 
    return db.delete("Job_Saved", null, null); 
} 
public long insertlocation(String Id,String Title,String Location,String State,String Company,String Description,String value, String Username,String Password) { 
    //DatabaseHelper d=new DatabaseHelper(DBAdapter.this); 
    ContentValues initialValues = new ContentValues(); 
    initialValues.put("Id", Id); 
    initialValues.put("Title", Title); 
    initialValues.put("Location", Location); 
    initialValues.put("State", State); 
    initialValues.put("Company",Company); 
    initialValues.put("Description", Description); 
    initialValues.put("Status", value); 
    initialValues.put("Username", Username); 
    initialValues.put("Password", Password); 
    return db.insert("Job_Saved", null, initialValues); 
} 
public ArrayList<Data> getAllData(){ 
    ArrayList<Data> arr = new ArrayList<Data>(); 
    Cursor c = db.query("Job_Saved", null, null, null, null, null, null); 
    if(c.getCount()>0){ 
     while(c.moveToNext()){ 
      Data f = new Data(); 
      f.setid(c.getString(0)); 
      f.setbusinessname(c.getString(1)); 
      f.setcityname(c.getString(2)); 
      f.setstatename(c.getString(3)); 
      f.setcompanyname(c.getString(4)); 
      f.setDesc(c.getString(5)); 
      f.setStatus(c.getString(6)); 
      f.setUser(c.getString(7)); 
      //f.setCharging(c.getString(8)); 
      arr.add(f); 
     } 

    } 
    c.close(); 
    return arr; 
} 
public void updateDownload(String id , String status) 
{ 
    ContentValues initialValues = new ContentValues(); 
    initialValues.put("status", status); 
    db.update("Likes", initialValues, "id=?", new String[] {id}); 
} 
public String getIdStatus(String id){ 
    String a=""; 
    Cursor c = db.query("Likes", null, "id='" + id + "'", null, null, null, 
      null);  
    if(c.getCount()>0){ 
     while(c.moveToNext()) 
     { 
     a=c.getString(1); 
     } 

    } 
    return a; 
} 

private class DatabaseHelper extends SQLiteOpenHelper { 
    DatabaseHelper(Context context) { 

     super(context, DATABASE_NAME, null, DATABASE_VERSION); 

     System.out.println("Constructor of DB Helper Class..."); 
    } 

    @Override 
    public void onCreate(SQLiteDatabase db) { 
     System.out.println("on create of database helper class.."); 

     try { 
      // Creating Database........................................... 
      db.execSQL(TABLE_DATA); 
     } 
     catch (Exception e) { 
      e.printStackTrace(); 
     } 
    } 


    @Override 
    public void onOpen(SQLiteDatabase db) { 
     // DBAdapter.this.db=db; 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     // Log.w(TAG, "Upgrading database from version " + oldVersion 
     // + " to " 
     // + newVersion + ", which will destroy all old data"); 
     // db.execSQL("DROP TABLE IF EXISTS users"); 
     // onCreate(db); 
    } 
} 

public String getFolderkeywordname(String string) { 
    String index = ""; 
    Cursor c = db.query("folders", new String[] { "keyword" }, "name='" + string + "'", null, null, null, 
      null);  
    if(c.getCount()>0){ 
     while(c.moveToNext()){ 
      System.out.println("folder id is : " + index); 
      index = c.getString(0); 

     } 
    } 
    c.close(); 
    return index; 
} 

}

Это мой адаптер базы данных класса. Я также определил класс getter And setter, но у меня нет идеи извлекать значение из базы данных. Так что, пожалуйста, помогите мне.

Я также хочу использовать выборки и запрос на удаление

Любая помощь приветствуется. Заранее спасибо.

Answer 1

Попробуйте это .... для получения данных

public Cursor FunctionName(String category) { 

    Cursor mCursor = ourDatabase 
      .query(true, DATABASE_TABLE_NAME, new String[] { 
        CATEGORY_ID, CATEGORY_NAME, CATEGORY_IMAGE }, 
        CATEGORY_IMAGE + "=?", new String[] { category }, null, 
        null, null, null); 

    return mCursor; 

} 

Для Удалять данных ....

public boolean deleteCategory(String id) { 
    // TODO Auto-generated method stub 
    return ourDatabase.delete(DATABASE_TABLE_NAME, CATEGORY_ID + "=?", new String[] { id }) > 0; 
}