Warning: Invalid argument supplied for foreach()

Question

i have this MySQL table for news categories:

id - name - parent

1: now I need to list parent/child categories into <optgroup><optgroup>.

PHP CODE:

$options    = array();
$categories = mysql_query("
  SELECT 
    id, name, p.name AS parent 
  FROM 
    " . CATS . " AS child
  INNER JOIN
    " . CATS . " AS p ON p.id = child.parent
");
foreach($categories as $category) { // LINE 734
  $parent = $category['parent'];
  if (! isset($options[$parent])) $options[$parent] = array();
  $options[$parent][$category['id']] = $category['name'];
}
echo "<select>";
foreach($options as $group => $option) {
  printf('<optgroup label="%s">', $group);
  foreach ($option as $id => $label) {
    printf('<option value="%s">%s</option>', $id, $label);
  }
  printf('</optgroup>');
}
echo "</select>";

PROBLEM:

Warning: Invalid argument supplied for foreach() in C:\xampp\htdocs\cms\news.php on line 734

UPDATE: I test with $categories array and see my code worked. if $categories MySQL result Like this:

$categories = array(
  array('id' => 1, 'name' => 'Label 1', 'parent' => 'Parent 1'),
  array('id' => 2, 'name' => 'Label 2', 'parent' => 'Parent 2'),
  array('id' => 3, 'name' => 'Label 3', 'parent' => 'Parent 1'),
  array('id' => 4, 'name' => 'Label 4', 'parent' => 'Parent 1'),
  array('id' => 5, 'name' => 'Label 5', 'parent' => 'Parent 1'),
  array('id' => 6, 'name' => 'Label 6', 'parent' => 'Parent 3'),
  array('id' => 7, 'name' => 'Label 7', 'parent' => 'Parent 8'),
  array('id' => 8, 'name' => 'Label 8', 'parent' => 'Parent 4'),
);

How To Fix My Problem!?

2: in update news page,I need To select News cats in this menu. My mean is: if $newscatid = $catid selected Option.(option value = $newscatid) How To update my code for this?

Did you read documentation about (mysql_query)[http://php.net/manual/en/function.mysql-query.php]? — sectus, Nov 02 '13 at 15:14
Add this line above line number 734 $categories=mysql_fetch_array($categories); — Altaf Hussain, Nov 02 '13 at 15:17
@AltafHussain: This Won't Work: `Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in line 735` — Alex.DX, Nov 02 '13 at 15:28
I’ve cast a vote so the question can be closed as a duplicate. — Mike Doe, Jan 30 '20 at 19:33

score 0 · Answer 1 · edited May 23 '17 at 11:57

0

You can't just call a query and use it like that. Your query returns a result set and you need to iterate through that. Try this

$query = mysql_query("
  SELECT 
    id, name, p.name AS parent 
  FROM 
    " . CATS . " AS child
  INNER JOIN
    " . CATS . " AS p ON p.id = child.parent
");
while($category = mysql_fetch_assoc($query)) {
  $parent = $category['parent'];
  if (! isset($options[$parent])) $options[$parent] = array();
  $options[$parent][$category['id']] = $category['name'];
}

Also, you really need to switch to mysqli Why shouldn't I use mysql_* functions in PHP?

edited May 23 '17 at 11:57

Community

1
1

answered Nov 02 '13 at 15:13

Machavity

30,841
27
92
100

This Won't Work: `Warning: mysql_fetch_assoc() expects parameter 1 to be resource, boolean given in line 735` – Alex.DX Nov 02 '13 at 15:26
Did you change line 726 to `$query`? I changed it for clarity – Machavity Nov 02 '13 at 15:32
No, I replace with `$categories`!! – Alex.DX Nov 02 '13 at 15:50
Ok, then it's likely your query failed then. Can you output [mysql_error](http://us.php.net/manual/en/function.mysql-error.php)? – Machavity Nov 02 '13 at 17:56

ogres · Answer 2 · 2013-11-03T10:04:14.073

-1

mysql_query function returns Resource not Array , check http://php.net/manual/en/function.mysql-query.php

try this

while($category = mysql_fetch_assoc($categories)){ // LINE 734
  $parent = $category['parent'];
  if (! isset($options[$parent])) $options[$parent] = array();
  $options[$parent][$category['id']] = $category['name'];
}

by the way , you are using deprecated mysql functions ...

edited Nov 03 '13 at 10:04

answered Nov 02 '13 at 15:14

ogres

3,660
1
17
16

This won't work. You have to have this inside a `while` loop. `foreach` expects an array. – Machavity Nov 02 '13 at 15:18

Warning: Invalid argument supplied for foreach()

2 Answers2