Sometimes we use MySql Views to organize related tables to make it easier to search and sort. For example if you have Posts with a Status, and a Source.
Post
subject
body
source_id
status_id
Status
id
label
other_field
Source
id
label
other_field
View
create view read_only_posts as
SELECT statuses.label as status, sources.label as source, posts.*
from posts
left join statuses on statuses.id = posts.status_id
left join sources on sources.id = posts.source_id
Then we have the Post model and an extra model:
// Post.php
class Post extends Model
{
//
}
// ReadOnlyPost.php
class ReadOnlyPost extends Post
{
protected $table = 'read_only_posts';
}
This is nice because now you can directly sort or filter on Status or Source as a string not the id's. You can also include the 'other_field'.
But we have a problem that I need help with. If you have a polymorphic many-to-many relationship on Posts, I can't get it to work on the read only version. For example if you have polymorphic tags:
// Post.php Model
public function tags()
{
return $this->morphToMany(Tag::class, 'taggable');
}
The problem is when you filter a post (using the read only model) with a specific tag you get sql like this:
select count(*) as aggregate from read_only_posts where exists (select * from tags inner join taggables on tags.id = taggables.taggable_id where read_only_posts.id = taggables.taggable_type and taggables.taggable_type = 'read_only_posts' and label = 'test')
As you can see the problem is the taggables.taggable_type = 'read_only_posts'.
I can't find a way to override the morph type for a model. (I am on laravel 5.4 and the MorphClass isn't there anymore). The morph map is an associative array so you can't do this:
// AppServiceProvider
public function boot()
{
Relation::morphMap([
'posts' => Post::class,
'posts' => ReadOnlyPost::class, <--- Can't do this
My stupid fix is when I attach a tag to a post I also attach it to ready_only_posts, which is kind of a mess.
Anyone else uses Views for read only models? Anyone have a better way to overriding the many to many polymorphic type for a specific model?
Looking at the code, I believe this might work.
class ReadOnlyPost extends Posts
{
public function getMorphClass() {
return 'posts';
}
}
In theory you should need to have the Posts model/table listed in the morph map, since the system will auto generate the type of "posts" for it based on naming.
Related
I am trying to show all posts of mine and my friends and also wanna show the comments on that posts
here is my controller
$user = Auth::user();
$friend_ids = $user->friends()->pluck('friend_id')->toArray();
$posts=PostModel::whereIn('users_id',$friend_ids)
->orWhere('users_id',Auth::user()->id)
->leftJoin('users as p_user','posts.users_id','=','p_user.id')
->leftJoin('post_comments','posts.id','=','post_comments.post_id')
->leftJoin('users as c_user','post_comments.friend_id','=','c_user.id')
-select('posts.caption','posts.image','posts.created_at','p_user.name','p_user.user_img as user_image','posts.id','c_user.user_img as commenter_img','post_comments.comment')
->get();
but the issue is that whenever any post have more than one comments it create more than one post and show one comment on any post , hope so you understand my question if not then I return my data here is the result
[{"id":5,"caption":"5thpost","image":"s1.jpg","name":"roger","user_image":"roger.jpg","commenter_img":"alex.jpg","comment":"nice one"},
{"id":5,"caption":"5thpost","image":"s1.jpg","name":"alex","user_image":"alex.jpg","commenter_img":"sufi.jpg","comment":"wow"}]
here you can see the id 5 is repeating I want to show all comments of id 5
You can go a step further and eager load from friends
$friends = $user->friends()->with(['posts.comments'])->get()
and you can chain on extra functions inside the with statement if required!
Likely you would want to add a between dates for the posts function for instance like:
$friends = $user->friends()->with(['posts' => function($q) use ($start, $end){
return $q->whereBetween('created_at', [$start, $end]);
},'posts.comments'])->get()
you can get the posts with $friends->posts and the comments with $friends->posts->comments and all the data you want will already be loaded and it stops N + 1 queries!
In Friends Model:
public function posts()
{
return $this->hasMany(Post::class);
}
In Post Model:
public function comments()
{
return $this->hasMany(Comments::class);
}
Don't use joins, use Model Relationships. Then you can eager-load related records like:
$posts = $postModel->with('comments')->where...
The result is that each Post Model within the Collection would have a nested attribute called 'comments', the name of the method within the Model that describes the relationship. And this 'comments' attribute would contain an Eloquent\Collection of Comment Model records.
When I try to access articles vie category it works properly here is category.php model
public function articles(){
return $this->belongsToMany('App\Article');
}
but when I try to access category name view article it doesn't work as it's supposed to, I made I mistake there and trying to fix it, but no luck so far. here is the Article model
public function category(){
return $this->hasOne('App\category');
}
and there is a table for relation those two to each others it's called article_category in page where I get all articles for the given tag, I want to do something like $article->category->name there is something sound very wrong to me but I can't figure it out.
The error I'm receiving is
Column not found: 1054 Unknown column 'category.article_id' in 'where clause' (SQL: select * from category where category.article_id = 1 and category.article_id is not null limit 1) (View: C:\wamp64\www\loremipsum\bluhbluhbluh\articleByTag.blade.php)
Btw the way I save the relationship for the article_category when an article is created is
$article->category()->sync($request->category, false);
You've said that article might have only one category. In this case, delete pivot table and add category_id into the articles table.
Then in the Article model define this relationship:
public function category()
{
return $this->belongsTo(Category::class);
}
And in the Category model:
public function articles()
{
return $this->hasMany(Article::class);
}
When you'll do that, you'll be able to access article's category with:
$article->category->name
You have the relationship established incorrectly. Remove the intermediate table and add category_id to the articles table.
Relationships are not set correctly
Category model should be like :
class Category extends Model
{
protected $table='category';
//give me all articles associated with the given category
public function articles()
{
return $this->hasMany('App\Article');
}
}
And Article model
class Article extends Model
{
protected $table='article';
//get the category associated with the given article
public function category()
{
return $this->belongsTo('App\Category');
}
}
for attaching articles to a category:
$article->category()->associate($category)->save();
This is the expected result of raw query
$sql = 'SELECT c.*
FROM catalogs c
LEFT JOIN (SELECT s.* FROM stock s WHERE s.date = "'.$dateOption.'") as sb
on sb.id_product = c.id_product
WHERE c.id_branch = '.Auth::user()->id_branch.';
$list = DB::select($sql);
I modified it using query builder, but the result is not correct
$lists = DB::table('catalogs')
->leftJoin('stock', 's.id_product','=','catalogs.id_product')
->where('s.date',$dateOption)
->where('catalogs.id_branch',Auth::user()->id_branch)
->get();
Anyone can tell me how should i write it in query builder?
Defining Relationships (more details)
The first argument passed to the hasOne method is the name of the related model. Once the relationship is defined, we may retrieve the related record using Eloquent's dynamic properties. Dynamic properties allow you to access relationship methods as if they were properties defined on the model:
namespace App;
use Illuminate\Database\Eloquent\Model;
class User extends Model
{
/**
* Get the phone record associated with the user.
*/
public function phone()
{
return $this->hasOne('App\Phone');
}
}
And then you can get the join like bellow.
$phone = User::find(1)->phone;
I'm new to laravel relationship so many apologizes if it's just dumb question. I'm using a pivot table named users_email on the project to get Emails of users. Pivot table contains the foreign key Uid and Email_id. Uid references users table
primary key and the same as Email_id. I can get the result while joining them using QueryBuilder.
$recent_inbox_email=DB::table('users_email')->
join('email','users_email.email_id','=','email.Id')->
join('users','users_email.Uid','=','users.Id')->
where('users_email.Uid','=',$Uid)->
where('email.draft','<>','true')->
where('email.trash','<>','true')->
where('email.status','=','unread')->count();
here's how I define the relationship in my models
public function getUid()//User Model
{
return $this->hasMany("User_Email",'Uid');
}
public function getEmId()//Email Model
{
return $this->hasMany("User_Email",'email_id');
}
//User_Email Model
public function email()
{
return $this->belongsTo('Email','Id','email_id');
}
public function user()
{
return $this->belongsTo('User','Id','Uid');
}
Now I want to query something like this using Eloquent
$query= select * from users_email inner join
email on users_email.email_id=email.Id
inner join users on users_email.Uid=users.Id
where users.Id=users_email.Uid limit 0,10
foreach($query as $emails)
{
echo $emails->f_name;
echo $emails->Message
}
DB designer Pic
Link to image
Thanks
There are no dumb questions. I'll try to give you an explanation! I'm not a pro, but maybe I can help.
Laravel uses some conventions that are not mandatory, but if you use them, things work like a charm.
For example, as a general recommendation, tables should be named in plural (your table users is ok. Your "email" table should be "emails"). The model, should be named in singular. This is User.php for table users, Email.php for table emails.
"The pivot table is derived from the alphabetical order of the related model names...", in this case "email_user". I repeat, you are not obliged to name them like this, as you can specify the table for the model setting the $table property in the model.
Once you have set up things like this, you only have to add this to your User model:
public function emails()
{
return $this->belongsToMany('Email');
}
And in your Email model:
public function users()
{
return $this->belongsToMany('User');
}
The "User" and "Email" between parentheses is the name of the related model.
And that's it. You can now do this:
$user = User::find(1);
foreach($user->emails as $email) {
echo $email->subject . '<br>';
echo $email->message . '<br>';
}
If you decide not to follow conventions, you can still use Eloquent relationships. You have to set up the relationship like this:
public function nameOfRelation()
{
return $this->belongsToMany('NameOfRelatedModel', 'name_of_table', 'foreign_key', 'other_key');
}
In the case of the User model for example:
public function emails()
{
return $this->belongsToMany('Email', 'users_email', 'Uid', 'email_id');
}
And in the email model, the other way round.
The answer got long! I didn't test the code, but this should give you an idea!
You can always check the official Laravel documentation, it is really helpful!
http://laravel.com/docs/4.2/eloquent
Hope I helped
Summary
I am building a music discovery service. My question is: How do I insert data into the three-way pivot table Tag_Track_User ?
Schema
I have this schema seen here at LaravelSD
It comprises of six main tables (and a few others):
Artists, Albums, Tracks, Tags, Users and Tag_Track_User
The Artists->Albums->Tracks relationship is straightforward and as you'd expect.
Tags, Tracks and Users all relate to one-another as no two can exist without the third.
Relationships
Artists hasMany() Albums
Albums hasMany() Tracks and belongsTo() an Artist
Tracks belongsTo() Albums
Tracks belongsToMany() Tags and belongsToMany() an Users
Tags belongsToMany() Tracks and belongsToMany() an Users
Users belongsToMany() Tags and belongsToMany() an Tracks
Models
User model
public function tags()
{
return $this->belongsToMany('Tag', 'tag_track_user', 'user_mdbid', 'tag_mdbid')->withPivot('track_mdbid');
}
/**
* #return \Illuminate\Database\Eloquent\Relations\BelongsToMany
*/
public function tracks()
{
return $this->belongsToMany('Track', 'tag_track_user', 'user_mdbid', 'track_mdbid')->withPivot('tag_mdbid');
}
The Tag and Track model contain the same respective relationships.
Question
So my question is:
How do I insert data into the Tag_Track_User table? The tag_track_user table is a 3-way pivot table cointaining information about tracks that users have tagged.
You have to be logged in to tag a track (which means I have access to the user’s ID). The tracks ID is accessed as I am displaying it on the page where the form is contained. The tag on the other hand; if it already exists in the tags table, I want to get it’s ID and re-use that (as they are unique), if not, I want to create it, assign it an ID and insert that into the tag_track_user_table.
I need to check whether the Tag exists
If it does, get it's ID
Insert data into the Tag_Track_User table
Thank you
Any help I receive on this, is greatly appreciated.
Well:
$tag = Tag::firstOrCreate(array('text' => $tag_text));
TagTrackUser::create(array(
"tag_mdbid" => $tag->mdbid,
"track_mdbid" => $track->mdbid,
"user_mdbid" => Auth::user()->mdbid
));
Something like that? firstOrCreate does what the name says it does, the rest is pretty straightforward Eloquent.
Since seems that there is not an appropriate pattern in Laravel, the cleaner and easier way is to implement any three-pivot-relationships via a model dedicated to the pivot table:
class Track
public function trackTags()
{
return $this->hasMany('TagTrack');
}
...
class Tag
public function tagTracks()
{
return $this->hasMany('TagTrack');
}
...
class TagTrack
public function track()
{
return $this->belongsTo('Track');
}
public function tag()
{
return $this->belongsTo('Tag');
}
public function anotherRelationship(){
...
}
You can do:
$track->trackTags->myCustomPivotDataAndRelationship()
and in TagTrack you have freedom to add as many relationship and field I want
Note than you can still keep the many to many to use when you don't need to access pivot relationships