Android联系人Content Provider返回同一联系人的多个副本，联系人中没有重复的联系人

public static String getContactName(Context context, String id, String address){

        if(id==null){
            if(address==null){
                return null;
            }else{
                return PhoneNumberUtils.formatNumber(address);
            }
        }

        Cursor cursor = context.getContentResolver().query(
                ContactsContract.Data.CONTENT_URI, 
                null, 
                null, 
                null, 
                null);

        if(cursor!=null){
            try{
                if(cursor.moveToFirst()){
                    do{
                        for(int i=0;i<cursor.getColumnCount();++i){
                            String columnName = cursor.getColumnName(i);
                            String columnText = cursor.getString(i);
                            Log.d(columnName, columnText==null ? "null":columnText);
                        }
                        Log.d("endline","***************************");
                    }while(cursor.moveToNext());


                }else{
                    Log.d("cursor", "not greater than 0");
                }
            }finally{
                cursor.close();
            }
        }

        if(address != null){
            return PhoneNumberUtils.formatNumber(address);
        }

        return "just testing shit";
    }
public static String getContactName(Context con