的Android的SQLite如何輸出數據庫的所有字段到ListView

Question

這是我的數據庫處理類 `

public class myDBHandler extends SQLiteOpenHelper { 

    private static final int DATABASE_VERSION = 1; 
    private static final String DATABASE_NAME = "todoDB.db"; 
    public static final String TABLE_TODO = "todo"; 
    public static final String COLUMN_ID = "_id"; 
    public static final String COLUMN_TODONAME = "todoName"; 
    public static final String COLUMN_DESCRIPTION = "description"; 



    public myDBHandler(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) { 
     super(context, DATABASE_NAME, factory, DATABASE_VERSION); 
    } 

    @Override 
    public void onCreate(SQLiteDatabase db) { 
     String query = "CREATE TABLE " + TABLE_TODO + "(" + 
       COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + 
       COLUMN_TODONAME + " TEXT " + 
       COLUMN_DESCRIPTION + "TEXT" + 
       ");"; 
     db.execSQL(query); 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     db.execSQL("DROP TABLE IF EXISTS " + TABLE_TODO); 
     onCreate(db); 
    } 

    //Add a new row to the database 
    public void addTODO(TODO todo){ 
     ContentValues values = new ContentValues(); 
     values.put(COLUMN_TODONAME, todo.get_todoname()); 
     values.put(COLUMN_DESCRIPTION,todo.get_description()); 
     SQLiteDatabase db = getWritableDatabase(); 
     db.insert(TABLE_TODO, null, values); 
     db.close(); 
    } 

    //Delete a TO DO from the database 
    public void deleteTODO(String TODOName){ 
     SQLiteDatabase db = getWritableDatabase(); 
     db.execSQL("DELETE FROM " + TABLE_TODO + " WHERE " + COLUMN_TODONAME + "=\"" + TODOName + "\";"); 
    } 

    public void editTODO(String TODOName, String newDescription){ 
     SQLiteDatabase db = getWritableDatabase(); 
     String queryUpdate = "UPDATE" + TABLE_TODO + "SET" + COLUMN_DESCRIPTION + "=\"" + newDescription + "WHERE" + COLUMN_TODONAME + "=\"" + TODOName + "\";"; 
     db.execSQL(queryUpdate); 
    } 

    public String dbToString(){ 
     String dbString = ""; 
     SQLiteDatabase db = getWritableDatabase(); 
     String query = "SELECT * FROM " + TABLE_TODO + " WHERE 1"; 

     //Cursor points to a location in your results 
     Cursor c = db.rawQuery(query, null); 
     //Move to the first row in your results 
     c.moveToFirst(); 

     //Position after the last row means the end of the results 
     while (!c.isAfterLast()) { 
      if (c.getString(c.getColumnIndex("todoName")) != null) { 
       dbString += c.getString(c.getColumnIndex("todoName")); 
       dbString += c.getString(c.getColumnIndex("description")); 

       dbString += "\n"; 
      } 


      c.moveToNext(); 
     } 
     db.close(); 

     return dbString; 
    }  
} 

我怎麼能輸出的列todoName &描述列表視圖在一個單獨的活動，從而使select *語句顯示這些列。代碼在這裏：

Answer 1

錯誤聲明

String query = "SELECT * FROM " + TABLE_TODO + " WHERE 1"; // WHERE 1 =?? 

查詢將不存在

增強您的WHERE聲明DEMO

String query = "SELECT * FROM " + TABLE_TODO + " WHERE " + FIELD_ID + " = '" + field_id_value + "'"; 

抓取所有的價值

// Select All Fields 
    String query = "SELECT * FROM " + TABLE_TODO ;