Notice: Trying to get property 'blood_group' of non-object Call Stack #TimeMemoryFunctionLocation 10.0010408992

PHP
1

I am trying to add some features on an old project. But this happens when i try to edit some data. Any Idea where I am getting wrong.

My code


<?php 
//session already set in config file
ini_set('display_errors', '1');
ini_set('display_startup_errors', '1');
error_reporting(E_ALL);

include('config/db.php');



$id = $_GET['id'];

$sql = "SELECT * FROM bloodgroups WHERE id=:id";

$query = $dbh -> prepare($sql);

$query -> execute([':id' => $id ]);

$result = $query ->fetch(PDO::FETCH_OBJ);


if ($_SERVER['REQUEST_METHOD'] == 'POST') {
  
    $blood_group = $_POST['blood_group'] ;

    $sql = "UPDATE bloodgroups set blood_group = :blood_group WHERE id=:id";
    
    $query = $dbh -> prepare($sql);

    if ($query -> execute([':blood_group' => $blood_group, ':id' => $id])) {
      
      header("location: editBloodGroup.php");
    }
     
}

?>

<?php include('routes/header.php');?>

<?php include('routes/topbar.php');?>

<?php include('routes/sidebar.php');?>



<div class="content-wrapper">
    <div class="content-header">
      <div class="container-fluid">
        <div class="row mb-2">
          <div class="col-sm-6">
          </div>
        </div>
      </div>
    </div>
      

<section class="content">
 <div class="container-fluid">
  <div class="row">
    <div class="col-8">

      <div class="card">
        <div class="card-header">
          EditBlood 
        </div>
        <div class="card-body">
          <form class="form-inline" action=""  id="form" method="POST">
          <div class="form-group mx-sm-3 mb-2">
            <input type="text" value="<?= $result->blood_group; ?>" name="blood_group" id="blood_group" class="form-control" >
          </div>
          <button type="submit" class="btn btn-primary mb-2">Submit</button>
        </form>
        
        </div>
 </div>
 
 </div>
   </div>
 </div>
  </section>
 </div>
  
<?php include_once 'routes/footer.php';?>
2

i dont’t see what your problem is with understanding the error message. you can debug every variable with var_dump().

3

When your form submits, and you execute the code inside this if() clause:

if ($_SERVER['REQUEST_METHOD'] == 'POST') {

won’t there be no value for $id at that point? In turn that would cause the query to fail, but your code doesn’t check whether it ran or not before using the results.

5

Done that code is working perfectly…

6

The same code works in my older system, without any errors.

7

Does it happen when you bring up the form to edit the data, or when you try to store the edited data?

8

then you have to start the debug process again, use var_dump()

9

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222660×199 1.76 KB

When i click the edit button the select id is selected thus the data is populated but editing it is the challenge now.

the error

11
11862×122 5.91 KB

11

The other problem you’ll have in there is that by the time you come to process the form submission, the $id variable will have gone away.

What do you get if you var_dump($POST) just inside the if($_SERVER clause?

12

editBloodGroup.php:24:string ‘POST’ (length=4)

13

Sorry, typo, I meant var_dump($_POST); to see the contents of the form array.

14

C:\wamp64\www\Raw\bloodbank\backend\editBloodGroup.php:46:
 array (size=2)
‘title’ => string ‘B+’ (length=2)
‘submit’ => string ’ ’ (length=0)

15

The problem is you named the field title but are expecting blood_group.

16

It was just another try out which i did and forgot to change… The code i posted above is the one I am using. Sorry for that.

17

And what does the var_dump() show when you use the actual code, not the code you were trying out?

18

The output

C:\wamp64\www\Raw\bloodbank\backend\editBloodGroup.php:46:
 array (size=2)
‘title’ => string ‘B+’ (length=2)
‘submit’ => string ’ ’ (length=0)
[/quote]

19

I thought that was with the code you were trying out, where you’d changed the form field name from “blood_group” to “title”? If not, then there’s your answer - you don’t have a form field called “blood_group”, and that’s why you get the error.

20

Alright…

21

Is this the right way the code should be or I should add some code???

22

When you say “this”, what code are you referring to? The code you posted earlier is not producing that var_dump() output because the field names don’t match the fields in the source code. Post the code you have now.