How to fix "notice: undefined index" and "notice: trying to access array offset on value of type null" using PHP

Question

1.00/5 (1 vote)

See more:

Notice: Undefined index: id_buku in D:\xampp\htdocs\tokobuku\page\admin\e_book.php on line 3

Notice: Undefined index: kategori in D:\xampp\htdocs\tokobuku\page\admin\e_book.php on line 10

Notice: Trying to access array offset on value of type null in D:\xampp\htdocs\tokobuku\page\admin\e_book.php on line 13

What I have tried:

<?php
include"../../config.php";
	$id_buku = $_POST['id_buku'];
	$judul = $_POST['judul'];
	$penerbit = $_POST['penerbit'];
	$pengarang = $_POST['pengarang'];
	$halaman = $_POST['halaman'];
	$harga = $_POST['harga'];
	$stok = $_POST['stok'];
	$kategori= $_POST['kategori'];
	$qryid = mysqli_query($con,"SELECT * FROM kategori where kategori='$kategori'");
	$data = mysqli_fetch_array($qryid);
	$id_kategori = $data['id_ketegori'];

@$message		= '';
$valid_file		= true;
$max_size		= 1024000;


if($_FILES['gambar']['name']){
	
	if(!$_FILES['gambar']['error']){

		$new_file_name = strtolower($_FILES['gambar']['tmp_name']); 
		if($_FILES['gambar']['size'] > $max_size)
			$valid_file	= false;
			$message	= 'Maaf, file terlalu besar. Max: 1MB';
		}
	
		$image_path = pathinfo($_FILES['gambar']['name'],PATHINFO_EXTENSION); 
		$extension = strtolower($image_path); 

		if($extension != "jpg" && $extension != "jpeg" && $extension != "png" && $extension != "gif" ) {
			$valid_file = false;
			$message	= "Maaf, file yang diijinkan hanya format JPG, JPEG, PNG & GIF. #".$extension;
		}



	
		if($valid_file == true)
		{
		
			$rename_nama_file	= date('YmdHis');
			$nama_file_baru		= $rename_nama_file.'.'.$extension;


			
			mysqli_query($con,"UPDATE buku set judul='$judul',id_ketegori='$id_kategori',pengarang='$pengarang',penerbit='$penerbit',halaman='$halaman',harga='$harga', gambar='$nama_file_baru', stok='$stok' where id_buku='$id_buku'");
		
			move_uploaded_file($_FILES['gambar']['tmp_name'], '../../gambar/'.$nama_file_baru);
			header("location:index.php?page=buku");
		}
	}
	
	else
	{

		$message = 'Ooops!  Your upload triggered the following error:  '.$_FILES['gambar']['error'];
	}
?>

Posted 23-May-21 7:59am

Hyunsuk Choi

Updated 23-May-21 16:35pm

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Wendelius · Answer 1 · 2021-05-23T16:35:00

The two firs messages indicate that the value for those indices is not set. Before fetching the values, you can use PHP: isset - Manual[^] to investigate if the value is actually set or not.

The third message seems like you might have a typo. Instead of

$data['id_ketegori'];

Should it be

$data['id_kategori'];

Then about the query, always use parameterized queries. Using the values directly leaves you wide open to SQL injection - Wikipedia[^]

For parameterized queries, have a look at for example PHP: Prepared Statements - Manual[^] and PHP: mysqli::prepare - Manual[^].