Laravel查询联接给出了尝试获取非对象的属性

Question

My Child Class

class Child extends Eloquent { ... public function campaign() { return $this->hasOne('Campaign'); } ... }

Here is my query in Laravel:

    $query = Child::query();
    $query->select('children.*');
    $query->join('demands', 'demands.children_id', '=', 'children.id')->where('demands.accepted', '=', '1');
    $children = $query->orderBy(DB::raw('RAND()'))->take(4)->get();

In in foreach ($children as $child), I try to call echo $child->campaign->name and I got "Trying to get property of non-object" message. $child->name works fine!

Answer 1

So as it turned out, not every children had a campaign associated with it. Just add a little check in your foreach loop and you should be fine

foreach($children as $child){
    if($child->campaign == null){
        continue;
    }
    // do stuff
}