Ok, really quite stuck at the moment trying to wrap my head around relationships and how best to use them between my Controller and my View. I'm very new to MVC and Laravel so please bear with me through any mistakes.
I've got 2 tables, very basic stuff. One is, let's say a 'posts' table, the other an 'authors' table. Each post will have the usual stuff, 'title', 'comment and 'author_id'. The author_id links the posts table to the author table. Obviously each post can only have one author, but an author can have many posts.
I currently have a controller that acts as an index to pull all of the information from the posts table ($posts = Post::all();) and this is passed to my view so I can cycle through it and print it out.
For each post, I need to match the author_id with the author_name but from what I've read and understand about MVC, I want to keep my logic out of my view, is there a way of doing this that I've missed? If I cycle through and match the id in my controller, only one author_id is passed to my view. Do I just have to run the query in a foreach on my view to replace author_id with author_name?
Thanks for your help!
If you've setup the belongsTo relationship between Post and Author, Eloquent will handle this for you automatically. For example:
$posts = Post::with('author')->all();
executed within your controller will retrieve the posts and will eager load the associated authors. Then, within your view, you could do:
@foreach ($posts as $post)
{{ $post->author->author_name }}
@endforeach
For each of your Post models, the Author model will already be associated to it (assuming your belongsTo was defined within a method called 'author()').
When setting up the relationship, do I need to set up both ends of the relationship? For example, my Post model set up as belongsTo Author and also set up Author to hasMany Posts or will just the belongTo suffice? That does explain how Eloquent makes processing any data with a relationship easier though, thank you!
You only need the hasMany if you need to resolve something going the other way. In my above example, simply having the belongsTo defined within Post will work for that.
Note that the "with()" isn't required in that case, but when you include it, Eloquent will pull all relevant author information in with a single query (eager loading) rather than every iteration through your "foreach $posts" loop causing an additional query against your authors table. This is often referred to as the N+1 problem since a single query for 10 posts results in 11 queries (one for the posts and one for each author of each post).
Ah, I now have it working thank you so much! Eager loading is definitely what I had in mind, because iterating over 100 posts would clearly take a while if each resulted in a query, so thanks again.
One thing I had to change from your code example above, though, was
$posts = Post::with('author')->all();
to
$posts = Post::with('author')->get();
because it was returning "Call to undefined method Illuminate\Database\Query\Builder::all()". Not sure if I have something a little different on my end but it's working smoothly now!
I am following this thread to get my code running but getting this error | '''QueryException in Connection.php line 647:
SQLSTATE[42S02]: Base table or view not found: 1146 Table 'martin.applications' doesn't exist (SQL: select * from applications where applications.id in (0))'''|
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