Laravel 4 : Value must be provided - php

Question

I use Laravel in a basic wamp server
I've got the error Value must be provided.
this is the controller code :
public function edit($id)
{
$query = DB::table('submenus');
$content = Content::find($id);
$galleries = Gallery::where('parent_id', '<>', $content->parent_id)->lists('parent_id', 'id');
$contents = Content::where('parent_id', '<>', $content->parent_id)->lists('parent_id', 'id');
$this_parent = Submenu::where('id' , '=' , $content->parent_id)->first();
/*if (!empty($galleries))
{
$query->whereNotIn('id', $galleries);
}
if (!empty($contents))
{
$query->whereNotIn('id', $contents);
}*/
$submenus = $query->lists('name', 'id');
asort($submenus);
$submenus[null] = "Aucun";
$this->layout->content = View::make('contents.edit', array(
"content" => $content,
"submenus" => $submenus,
"contents" => $contents,
"galleries" => $galleries
));
}
And the error message :
InvalidArgumentException
Value must be provided.
From: C:\webroot\okalli\rest\vendor\laravel\framework\src\Illuminate\Database\Query\Builder.php
// and keep going. Otherwise, we'll require the operator to be passed in.
if (func_num_args() == 2)
{
list($value, $operator) = array($operator, '=');
}
elseif ($this->invalidOperatorAndValue($operator, $value))
{
throw new \InvalidArgumentException("Value must be provided.");
}
I really don't know what is the problem..

Answer 1

It seems that $content->parent_id is null for the record you find and when you use <> operator it will throw this exception (null is allowed only for = operator).
Make sure you get from database what expect and you have parent_id column filled properly.
Quick solution would be using ternary operator:
$galleries = Gallery::where('parent_id', '<>', ($content->parent_id) ?: 0 )->lists('parent_id', 'id');
$contents = Content::where('parent_id', '<>', ($content->parent_id) ?: 0 )->lists('parent_id', 'id');
instead of
$galleries = Gallery::where('parent_id', '<>', $content->parent_id)->lists('parent_id', 'id');
$contents = Content::where('parent_id', '<>', $content->parent_id)->lists('parent_id', 'id');