i cant display posts' category with manyToMany relationship. i build relationship but can't display it.
// here is my post model
public function getCategory(){
return $this->belongsToMany(Category::class,
'post_categories','id','post_id');
}
// here is my controller
public function Allindex(){
$posts=Post::all();
return view('allposts',compact('posts'));
}
//here is my allposts blade
<div class="media-body">
<h4 class="media-heading">{{$post->pivot['name']}}</h4>
{{$post->created_at}}
</div>
You are passing the wrong param in a model relationship.
public function getCategory(){
return $this->belongsToMany(Category::class,'post_categories','post_id','category_id');
}
Now you can access it as below.
#foreach($post->getCategory as $category)
{{ $category->name }}
#endforeach
Or
{{ $post->getCategory->pluck('name')->implode(',') }}
Laravel is not automatically loading your relationship, the keyword you are looking for is eager loading.
You can eager load relationships with the with method like so:
$posts = Post::with('getCategory')->get();
Related
firstly, i'm a newbie in laravel.
i insert a array data as a string in server.
column name "category_id" & value like "1,2,3,4".
Now i just want to show these id's category name with eloquent relationship.
Using laravel latest version.
view page
{{$category_var = explode(',',$post->category_id)}}
#foreach($category_var as $category)
#if($category)
<span class="badge mb-3">{{$post->category->category}} </span>
#endif
#endforeach
class page
public function category(){
return $this-> belongsTo(Category::class);
}
Controller page
public function index()
{
$posts = post::paginate(9);
return view('pages/home',compact('posts'));
}
anything else need just ask me.
Thanks
just use the benefits of models and relation like below:
#foreach($posts as $post)
#foreach($post->category as $category)
<span class="badge mb-3">
{{ $category->(what ever you want from category model) }}
</span>
#endforeach
#endforeach
i have problem in laravel eloquent relationships.
there is 2 model in my application: article and category.
article model:
public function category()
{
return $this->belongsToMany('App\Category');
}
category model:
public function article()
{
return $this->hasMany('App\Article');
}
the relation between this tow is hasMany (Category -> article) & belongsToMany (Article -> category).
category will fetch by requested slug using this method at categoryController:
$category = Category::where('slug', '=', $slug)->get();
problem will be shown in view when i want to fetch articles from category and nothhing will return back:
#foreach ($category->article->all() as $article)
{{ $article->name }}
#endforeach
and from #dd($category->article) we will get empty collection:
Collection {#323 ▼
#items: []
}
As #lagbox tried to highlight in a comment, for pivot tables, both relationships should be belongsToMany. Inverse of hasMany is belongsTo.
If one article belongs to many categories, and one category can have many articles, then, ideally, there it should be a many-to-many relationship. Category model should have a belongsToMany relationship with Article model and vice versa. Additionally, there should be a pivot table, article_category. And as many have suggested, you can get articles the belongs to a category by using #foreach($category->articles as $articles)
You can read more about many to many here:
https://laravel.com/docs/5.8/eloquent-relationships#many-to-many
You can use #forelse blade directive like
#forelse ($category->article as $article)
<li>{{ $article->name }}</li>
#empty
<p>No articles</p>
#endforelse
You can check that here
You dont need to write $category->article->all() . $category->article itself will return all articles.
So just use like,
#foreach ($category->article->all() as $article)
{{ $article->name }}
#endforeach
For eager loading articles, you can use
with keyword
$category = Category::with('article')->where('slug', '=', $slug)->get();
Just an example:
let's say I have Post model, and the Comment model. Post, of course, have Comments, one-to-many relation.
I have to display list of posts with comments below it.
I'll get my posts in the controller:
$posts = Post::get(), I'll pass it to the blade view and then I'll loop through it
#foreach($posts as $post)
{{ $post->title }}
{{ $post->comments }}
#endforeach
where $post->comments is some relation
public function comments()
{
return $this->hasMany(Comment::class);
}
As we know, that query will be executed many times.
Now my question: how we should optimize it?
Return Cache::remember in the getter?
Get (somehow?) those comments, when getting the posts in one query? Something like join query? I know that I can write that kind of query, but I'm talking about Eloquent's query builder. And then how get the comments within the loop? Wouldn't {{ $post->comments }} call the relation again instead of getting stored data?
Different solution?
You can do $posts = Post::with('comments')->get() to eager load the comments with the post. Read more about it in the documentation: https://laravel.com/docs/5.7/eloquent-relationships#eager-loading
Also, to display the comments you would want to add another foreach loop. It would look something like this:
#foreach($posts as $post)
{{ $post->title }}
#foreach($post->comments as $comment)
{{ $comment->title }}
#endforeach
#endforeach
You’ve probably cached some model data in the controller before, but I am going to show you a Laravel model caching technique that’s a little more granular using Active Record models
Note that we could also use the Cache::rememberForever() method and rely on our caching mechanism’s garbage collection to remove stale keys. I’ve set a timer so that the cache will be hit most of the time, with a fresh cache every fifteen minutes.
The cacheKey() method needs to make the model unique, and invalidate the cache when the model is updated. Here’s my cacheKey implementation:
public function cacheKey()
{
return sprintf(
"%s/%s-%s",
$this->getTable(),
$this->getKey(),
$this->updated_at->timestamp
);
}
public function comments()
{
return $this->hasMany(Comment::class);
}
public function getCachedCommentsCountAttribute()
{
return Cache::remember($this->cacheKey() . ':comments_count', 15, function () {
return $this->comments->count();
});
}
yes u can do like that in controller
$minutes = 60;
$posts = Cache::remember('posts', $minutes, function () {
return Post::with('comments')->get()
});
in blade u can get like that
#foreach($posts as $post)
{{ $post->title }}
#foreach($post->comments as $comment)
{{ $comment->title }}
#endforeach
#endforeach
for more information read this article
AdminsController
public function index(){
$someMessages=$this->blog->paginate(5);
$users=User::all();
// return 'Welcome Admin';
return View::make('admin.admin',['someMessages'=>$someMessages,'users'=>$users]);
}
admin.blade.php
Here need to display username from 'users' variable based on uid stored in 'someMessages' object.
#extends('layout.default')
#section('title')
<title>Welcome Admin</title>
#stop
#section('content')
#foreach($someMessages as $message)
<blockquote>{{$message['blog']}}
<small>
<cite>
</cite>
</small>
</blockquote>
#endforeach
{{ $someMessages->links()}}
#stop
If you have a Eloquent relation between blog messages and users defined correctly you don't need to query the users separately. What you want to do is just go with the eager loading:
//in case you call it author in your "relation definition"
$someMessages = $this->blog->with('author')->paginate(5);
And then in your Blade template:
#foreach($someMessages as $message)
<div>
<div>{{ $message->blog }}</div>
<div>{{ $message->author->name }}</div>
</div>
#endforeach
If you haven't declared the relationship yet - it's easy. Open up your user eloquent model class and add a method:
public function blogs()
{
return $this->hasMany('Blog', 'uid');
}
In the blog eloquent model class you'd add:
public function author()
{
return $this->belongsTo('User', 'uid');
}
More about eloquent and relationships can be found here.
If that's not the case you can still filter your users collection to get the one you want:
#foreach($someMessages as $message)
<?php
$user = $users->filter(function($user) use ($message)
{
return $user->id == $message->uid;
})->first();
?>
<div>
<div>{{ $message->blog }}</div>
<div>{{ $user->name }}</div>
</div>
#foreach
What happens here is you filter your users collection based on $message->uid value and take the first one from it (it should always be just one or none since user IDs are unique).
Although you need to understand that in this case you will get all the users from database and filter through them for every blog message you're outputting. Eager loading is a much better idea here and I'd stick to it if possible.
I have "posts" table that has many-to-one relationship with "categories" table. The goal is to show all of posts and their categories.
Tables:
Posts: id, content, category_id, etc
Categories: id,name
Here's my code
Models:
class Posts extends Eloquent
{
public static $table = 'posts';
public function categories()
{
return $this->belongs_to('Categories');
}
}
class Categories extends Eloquent
{
public static $table = 'categories';
public function posts()
{
return $this->has_many('posts');
}
}
My controller
public function get_posts()
{
$posts = Posts::with('categories')->all();
return View::make('admin.posts')
->with('title', 'Posts')
->with('posts', $posts);
}
My view
#foreach($posts as $post)
<tr>
<td>{{ $post->title }}</td>
<td>{{ $post->categories->name }}</td>
<td><small> {{$post->updated_at}} </small></td>
<td>
<button>
{{HTML::link_to_route('edit_post','Edit',array($post->id))}}
</button>
{{Form::open('admin/delete','Delete')}}
{{Form::hidden('id', $post->id)}}
<input type="submit" name="edit_post" value="Delete"/>
{{Form::close()}}
</td>
</tr>
#endforeach
ERROR:
Error rendering view: [admin.posts]
Trying to get property of non-object
I am a newbie, please help me solve this issues
{{ $post->categories->name }} before test is categories exists
Example:
#if( ! empty($post->categories))
<td>{{ $post->categories->name }}</td>
#else
#end if
Aesis.
Just use ::all() instead of ::with(..)->all()
categories is an array as you are using a has_many relationship. There are many categories, hence an array is returned, so to access it you have to index it like an array
the correct solution would be
$post->categories[0]->name
Are you using Laravel 4? First the syntax for declaring relationship is hasMany and belongsTo, in camel case. Check it out in Laravel documentation
In view, check if categories are empty collection, ie., whether post has its category:
#if($post->categories->count())
<td>{{ $post->categories->name }}</td>
...
#endif
By the way, I would use singular form as model class name, like Post and Category instead of plural forms. And in Post class I would define inverse one-to-many relationship with singular form, to show there's only one entry in category table for this given Post.
public function category()
{
return $this->belongsTo('Category');
}