搜索SQLite數據庫返回空遊標

Question

我正在使用searchView來獲取查詢以使用字符串搜索數據庫，遊標不返回爲空但是爲空。

呼叫從我的搜索活動搜索（這是實現SearchView.OnQueryTextListener一個ListActivity）：

@Override 
    public boolean onQueryTextChange(String newText) { 
     // TODO Auto-generated method stub 
     //handleIntent(intent); 
     Log.d("LIST ACTIVITY SEARCH", "onQueryTextCahanged called: "+ newText); 
     Cursor c = data.getWordMatches(newText, null); 

     Log.d("LISTACTIVITY", "CURSOR QUERY ROWS/COLS = "+ c.getCount()+" "+c.getColumnCount()); 

     //now set bind cursor data to list view using custim ItemAdpter class 
     adapter = new ItemAdapter(ViewListOfTests.this, c); 
     this.setListAdapter(adapter); 
     return false; 
    } 

而且在SQLite的Databasetaking搜索方法從方法的字符串上面的查詢：

/* 
    * methods to search database with String query form searchable widget intent 
    * in ViewListOfDives ListActivity search bar. Each search returns a cursor which is set to adpter 
    * in ViewListOfYesys List Activity 
    */ 

    public Cursor getWordMatches(String query, String[] columns){ 

     String selection = database.KEY_TESTNAME + " MATCH ?"; 
     String[] selectionArgs = new String[] {query+"*"}; //wildcard * 

     return query(selection, selectionArgs, columns); 


    }//end getWordMatches 



    private Cursor query(String selection, String[] selectionArgs, 
      String[] columns) { 

     // return cursor form params passed getWordMatches(Styring query) from search widget ListActivity 

     SQLiteQueryBuilder builder = new SQLiteQueryBuilder(); 
     builder.setTables(DATABASE_TABLE); 

     dbHelperObject = new DbHelper(ourContext); 

     Cursor cursor = builder.query(dbHelperObject.getReadableDatabase(), columns, selection, selectionArgs, null, null, null); 

     if(cursor == null){ 
      return null; 
     }else if(!cursor.moveToFirst()){ 
      cursor.close(); 
      return null; 
     } 

     return cursor; 




    }//end query 

else else代碼在此處執行時返回空遊標：

else if(!cursor.moveToFirst()){ 
       cursor.close(); 
       return null; 

任何輸入讚賞！ 夏蘭

Answer 1

明白了，看來我傳遞錯誤的參數給curosr.rawQuery（）。 我經過一個裁判數據庫輔助對象getReadableDB電話：

Cursor cursor = builder.query(mDatabaseOpenHelper.getReadableDatabase(), 
      columns, selection, selectionArgs, null, null, null); 

當我更換此參數與數據庫對象它工作得很好：

SQLiteDatabase ourDataBase = ourDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY); 

Cursor cursor = builder.query(ourDataBase, columns, selection, selectionArgs, null, null, null); 

中規定的培訓文件通過前mDatabaseOpenHelper.getReadableDatabase （）但這似乎不起作用，不是原因。 http://developer.android.com/training/search/search.html

Answer 2

，而不是這樣的：

if(cursor == null){ 
    return null; 
}else if(!cursor.moveToFirst()){ 
cursor.close(); 
    return null; 
} 

return cursor; 

使用本：

if(cursor == null){ 
    return null; 
}else{ 
    cursor.moveToFirst(); 
} 

return cursor;