trying to get property of non-objec error

Question

lets see code

public function chekfactor( $factor,$user) {    
               $arrfactor=preg_split('/<td>/',$factor);
                  $arrusers=preg_split('/<td>/',$user);
             $tedstore=count($arrusers) ;
              $tedkala=count($arrfactor) ;
               $inttedstore=(int) $tedstore;
 $inttedkala=(int)$tedkala;
$afa="0";
$a=(int)$afa;
 for (;$a<$inttedstore;){
  $storeusername=$arrusers[$a];
      $faktorss=$arrfactor[$a];
  $tablename='devlist'.$storeusername;
  echo   $tablename;
      echo   $faktorss;
           $result = $this->conn->query("SELECT id FROM'".$tablename."' WHERE prcode='".$faktorss."' ");

        if ($result->num_rows > 0) {
            while($row = $result->fetch_assoc()) {
                                    $user = array();
                    $user[$faktorss] = $row["id"];


              return $user;
            }
        }else {

             return "no";
        }


  $a++;
}

and give to me the errors

trying to get property of non-object on line 543 means " if ($result->num_rows > 0) { "

why happen and how fix it ?

that means you don't have result in `$result` add `if` condition to check it has value or not — Jigar Shah, Oct 03 '17 at 12:02
Your query syntax is off. You have quotes around the tablename, and no space between `FROM` and the tablename — Qirel, Oct 03 '17 at 12:08

score 2 · Answer 1 · edited Oct 03 '17 at 12:05

2

change the line

if ($result->num_rows > 0)

for

if (!empty($result)) // make sure it is having value then use `num_rows` on it

The issue is that you are trying to access to num_rows property when $result is empty.

edited Oct 03 '17 at 12:05

Jigar Shah

6,143
2
28
41

answered Oct 03 '17 at 12:02

Synkronice

179
1
9

2

It is better to use `isset` or `empty` instead of just an `if`. – teeyo Oct 03 '17 at 12:03
1

The value will always be set, it will either be an object or `false` - so checking on the variable directly is fine as this code is structured. – Qirel Oct 03 '17 at 12:11
I think that always where is possible we should use IF in a positive way, for to improve the reading. To use "if ($result)" is completely valid in a test environment. – Synkronice Oct 03 '17 at 12:33

score 1 · Accepted Answer · answered Oct 03 '17 at 12:42

i guess your query is not working because of your quotes and space

"SELECT id FROM'".$tablename."' WHERE prcode='".$faktorss."'";

query will print like

SELECT id FROM'table_1' WHERE..

you can change like

"SELECT id FROM ".$tablename." WHERE prcode=".$faktorss."";

adkstar · Answer 3 · 2017-10-03T12:20:53.393

0

You can do

if($result && !empty($result)){
   $num_rows = $result->num_rows;
   if($num_rows > 0){
     //the logic here
   }
}

edited Oct 03 '17 at 12:20

answered Oct 03 '17 at 12:05

adkstar

178
1
10

it will throw the same error as OP mentioned , problem is $result is empty so you can not access `num_rows` on it – Jigar Shah Oct 03 '17 at 12:08

trying to get property of non-objec error

3 Answers3