Up until now, I've been doing this to order by a model's relationship:
$users = User::leftJoin('user_stats', 'users.id', '=', 'user_stats.user_id')
->orderBy('user_stats.num_followers')
->get();
Here's the User model:
class User extends Model
{
/**
* The table associated with the model.
*
* #var string
*/
protected $table = 'users';
public function stats()
{
return $this->hasOne('App\Models\UserStat');
}
}
Is there a better way to orderBy a model's relationship without having to use any joins? I'm using Laravel 5.2.
You could use Collection instead:
$users = User::with('stats')->get()->sortBy(function($user, $key) {
return $user['stats']['num_followers'];
})->values()->all();
https://laravel.com/docs/5.2/collections#method-sortby
As long as the column you want to order by is on a different table (eg. on a related model), you'll have to join that table in.
The Collection sort:
The proposal by crabbly does not save you the join. It only sorts the collection manually in php, after the data has been fetched using a join.
Edit: In fact, the with('stats') generates no join, but instead a separate SELECT * FROM user_stats WHERE ID IN (x, y, z, …). So well, it actually saves you a join.
Maintain a copy:
A way of truly saving the join would be to have a copy of num_followers directly in the users table. Or maybe store it only there, so you don't have to keep the values in sync.
Related
Assume this:
class List extends Model
{
public function items(){
return $this->hasMany(Items::class, 'c.class_id', 'class_id')
->rightjoin('items_classes as c', 'c.items_id', '=', 'items.id');
}
}
The problem is that Eloquent prepends items to foreign key field and the final query is:
SELECT * FROM items
RIGHT JOIN items_classes as c ON c.items_id = items.id
// here it is
WHERE items.c.class_id = 10
Even using DB::raw('c.class_id') didn't solve the problem.
If you notice the signature of hasMany relation method :
return $this->hasMany(Model::class, 'foreign_key', 'local_key');
Which means when Laravel will make the query, it will consider second argument foreign_key as a column of table defined in Model::class.
To simplify in your case :
return $this->hasMany(Items::class, 'c.class_id', 'class_id')->...
Leaving the rightjoin aside for a moment, Laravel is considering c.class_id as a foreign key of Item::class table which is indeed items table.
So the resultant query is :
SELECT * FROM items WHERE items.c.class_id = 10
Then when you add the right join, laravel just adds into the main query and makes it :
SELECT * FROM items
RIGHT JOIN items_classes as c ON c.items_id = items.id
WHERE items.c.class_id = 10
Laravel will not refer items_classes in the relation because you are relating List Model to Item::class and not ItemClass::class.
I am not sure about the data you need but see if you can use with like below :
class List extends Model
{
public function items(){
return $this->hasMany(Items::class, 'c.class_id', 'class_id');
}
}
List::with(['items', function($q){
return $q->->rightjoin('items_classes as c', 'c.items_id', '=', 'items.id');
}])->get();
Hope this gives you an idea how you can update your relationships to get desired query. If you add your table structure and data you want, I can update the answer with relationships for you.
I have a complicated relationship I'm trying to establish between two models.
The goal is to use $supplier->supply_orders to access the orders where the user supplies an item.
This throws: LogicException: Relationship method must return an object of type Illuminate\Database\Eloquent\Relations\Relation.
With the code I've got I can use $supplier->supply_orders()->get(), however, when I try to use it as a relationship it throws. Since this is a relationship I should be able to wrap it in a relationship, but how would I go about doing that?
Supplier Model:
class Supplier extends Model {
public function supply_orders() {
return Order::query()
->select('order.*')
->join('item_order', 'order.id', '=', 'item_order.order_id')
->join('item', 'item_order.item_id', '=', 'item.id')
->where('item.supplier_id', '=', $this->id);
}
}
~~~ A whole lot of back info that I don't think you need but might ~~~
sql tables:
supplier
- id
items:
- id
- supplier_id
item_order:
- id
- order_id
- item_id
orders:
- id
The other Eloquent Models:
class Item extends Model {
public function orders() {
return $this->belongsToMany('Order');
}
}
class Order extends Model {}
Example of how this should work:
$supplier = factory(Supplier::class)->create();
$item = factory(Item::class)->create([
'supplier_id' => $supplier->id,
]);
$order = factory(Order::class)->create();
$order->items()->attach($item);
$orders = $supplier->supply_orders // Throws LogicException
This throws: LogicException: Relationship method must return an object of type Illuminate\Database\Eloquent\Relations\Relation
Sounds like a hasManyThrough with a many to many relationship. Laravel has no inbuilt support for this but you can always go ahead and write your own relationship like this: https://laravel.io/forum/03-04-2014-hasmanythrough-with-many-to-many
If you dont want relationships you can always do something like:
Order::whereHas('items.supplier', function($query) use($supplier) {
$query->where('id', $supplier->id);
});
For this to work, you need to have a relationship function items in your Order model and a relationship function supplier in your item model
I believe the reason it throws a relationship error is that you haven't created an Eloquent relation for
$supplier->supply_orders.
Instead, Laravel looks at your supply_orders() as a method in the class, and thus can't figure out which table to use as the pivot. To get the base relationship to work within Eloquent, you'd need to create a new pivot table for the relationship between suppliers and orders something like:
suppliers
-id
orders
-id
order_supplier
-id
-order_id
-supplier_id
From here, Laravel will accept a simple many to many relationship between the two (this would not cause a failure):
Supplier Class:
/**
* Get all orders associated with this supplier via order_supplier table
*
* #return \Illuminate\Database\Eloquent\Relations\BelongsToMany
*/
public function orders(){
return $this->belongsToMany("\App\Order");
}
Now that the relationship is solid both between the suppliers and orders, as well as the orders and items, you can eager load the relationship in all directions. Where it gets complicated for your particular need with the current DB setup is that you have a 3rd parameter from the items table that is not a direct pivot. Without having to re-structure the DB, I think the easiest would be to load your suppliers and the relationships like normal:
$suppliers = Supplier::with('orders', function($query) {
$query->with('items');
});
From here you've got all the relationships loaded and can draw down the ones with the right item->ids in a follow-up to the $suppliers collection. There are quite a few ways to skin the cat (even including all in one query) now that you have the Eloquent relationship... but I tend to keep it a little more simple by breaking it into a few readable bits.
Hope this helps.
I have the following table:
The table is called user_eggs and it stores the user eggs.
eggs are items with additional data (hatch_time)
As you can see, user 2 has 2 eggs, which are items 46 and 47.
My items table stores the item general information such as name, image, description, etc...
How I can return the user eggs using $user->eggs() including the item data in my items table of the egg item_id?
I tried:
User Model:
/**
* Get the eggs
*/
public function eggs()
{
return $this->belongsToMany(Egg::Class, 'user_eggs','user_id','item_id')
->withPivot('id','hatch_time');
}
but $user->eggs() returns an empty array.
Any ideas?
A simple approach will be:
in your UserEgg model define:
/**
* Get the user associated with egg.
*/
public function _user()
{
return $this->belongsTo('App\User','user_id');
}
/**
* Get the item associated with egg.
*/
public function item()
{
return $this->belongsTo('App\Item','item_id');
}
then in your controller:
use the model to extract everything like this:
$userEggs = UserEgg::where('user_id',2)->get();
foreach($userEggs as $userEgg){
$associateduser = $userEgg->_user;
$associatedItem = $userEgg->item;
}
Short answer
If you loop through the user's eggs:
foreach($user->eggs as $egg){
$item = Item::find($egg->pivot->item_id);
}
If you want to query:
$user->eggs()->wherePivot('item_id', 1)->get();
Long answer
From the Laravel Documentation
Retrieving Intermediate Table Columns
As you have already learned, working with many-to-many relations requires the presence of an intermediate table. Eloquent provides some very helpful ways of interacting with this table. For example, let's assume our User object has many Role objects that it is related to. After accessing this relationship, we may access the intermediate table using the pivot attribute on the models:
$user = App\User::find(1);
foreach ($user->roles as $role) {
echo $role->pivot->created_at;
}
Notice that each Role model we retrieve is automatically assigned a pivot attribute. This attribute contains a model representing the intermediate table, and may be used like any other Eloquent model.
By default, only the model keys will be present on the pivot object. If your pivot table contains extra attributes, you must specify them when defining the relationship:
return $this->belongsToMany('App\Role')->withPivot('column1', 'column2');
If you want your pivot table to have automatically maintained created_at and updated_at timestamps, use the withTimestamps method on the relationship definition:
return $this->belongsToMany('App\Role')->withTimestamps();
Filtering Relationships Via Intermediate Table Columns
You can also filter the results returned by belongsToMany using the wherePivot and wherePivotIn methods when defining the relationship:
return $this->belongsToMany('App\Role')->wherePivot('approved', 1);
return $this->belongsToMany('App\Role')->wherePivotIn('priority', [1, 2]);
I am new with Laravel, I was able to query Many-to-Many relationships. Where 'template_dynamic' is the pivot of two tables 'template' and 'dynamic'.
// Template Model
class Template extends Eloquent
{
protected $table = 'template';
protected $guarded = array('template_id');
protected $primaryKey = 'template_id';
public function dynamic()
{
return $this->belongsToMany('dynamic', 'template_dynamic')
->select('*')
->withPivot('template_dynamic_id')
->orderBy('template_dynamic_html_sort', 'ASC');
}
here I was able to retrieve the records
// Template Controller
$dynamic_fields = Template::find($rec->template_id)->dynamic;
what I want to do now is that pivot table has-many properties 'template_dynamic_option'. How will I query the records and combine it with $dynamic_fields variable?
// What I want to do is something like this. But sadly this is an invalid syntax
$dynamic_fields = $dynamic_fields->with('template_dynamic_option');
Any recommendation or enhancements are welcome.
Thank you in advance.
First, I am pretty sure you don't need the select('*') in your relationship query there.
But let's get to your actual problem ;)
To access the pivot table in Eloquent is pretty simple.
$dynamic_fields = Template::find($rec->template_id)->dynamic;
foreach($dynamic_fields as $dynamic){
var_dump($dynamic->pivot)
}
The thing is though, by default only the keys of the pivot table are present in the object.
To change that you have to define them with withPivot(). Actually like you already did but not with the id.
public function dynamic()
{
return $this->belongsToMany('dynamic', 'template_dynamic')
->withPivot('template_dynamic_option')
->orderBy('template_dynamic_html_sort', 'ASC');
}
And if you have multiple additional columns use this syntax:
->withPivot('template_dynamic_option', 'foo', 'bar');
I have a collection of objects. Let's say the objects are tags:
$tags = Tag::all();
I want to retrieve a certain attribute for each tag, say its name. Of course I can do
foreach ($tags as $tag) {
$tag_names[] = $tag->name;
}
But is there a more laravelish solution to this problem?
Something like $tags->name?
Collections have a lists method similar to the method for tables described by #Gadoma. It returns an array containing the value of a given attribute for each item in the collection.
To retrieve the desired array of names from my collection of tags I can simply use:
$tags->lists('name');
Update: As of laravel 5.2 lists is replaced by pluck.
$tags->pluck('name');
More specifically, the laravel 5.2 upgrade guide states that "[t]he lists method on the Collection, query builder and Eloquent query builder objects has been renamed to pluck. The method signature remains the same."
Yep, you can do it nice and easily. As the Laravel 4 Documentation states, you can do
Retrieving All Rows From A Table
$users = DB::table('users')->get();
foreach ($users as $user)
{
var_dump($user->name);
}
Retrieving A Single Row From A Table
$user = DB::table('users')->where('name', 'John')->first();
var_dump($user->name);
Retrieving A Single Column From A Row
$name = DB::table('users')->where('name', 'John')->pluck('name');
Retrieving A List Of Column Values
$roles = DB::table('roles')->lists('title');
This method will return an array of role titles.
You may also specify a custom key column for the returned array:
$roles = DB::table('roles')->lists('title', 'name');
Specifying A Select Clause
$users = DB::table('users')->select('name', 'email')->get();
$users = DB::table('users')->distinct()->get();
$users = DB::table('users')->select('name as user_name')->get();
EDIT:
The above examples show how to access data with the help of Laravel's fluent query builder. If you are using models you can access the data with Laravel's Eloquent ORM
Because Eloquent is internaly using the query builder, you can without any problem do the following things:
$tag_names = $tags->lists('tag_name_label', 'tag_name_column')->get();
which could be also done with:
$tag_names = DB::table('tags')->lists('tag_name_label', 'tag_name_column')->get();
Here are a few snippets from my own experimentation on the matter this morning. I only wish (and maybe someone else knows the solution) that the Collection had a $collection->distinct() method, so I could easily generate a list of column values based on an already filtered collection.
Thoughts?
I hope these snippets help clarify some alternative options for generating a list of unique values from a Table, Collection, and Eloquent Model.
Using a Collection (Happy)
/**
* Method A
* Store Collection to reduce queries when building multiple lists
*/
$people = Person::get();
$cities = array_unique( $people->lists('city') );
$states = array_unique( $people->lists('state') );
// etc...
Using an Eloquent Model (Happier)
/**
* Method B
* Utilize the Eloquent model's methods
* One query per list
*/
// This will return an array of unique cities present in the list
$cities = Person::distinct()->lists('city');
$states = Person::distinct()->lists('state');
Using an Eloquent Model PLUS Caching (Happiest)
/**
* Method C
* Utilize the Eloquent model's methods PLUS the built in Caching
* Queries only run once expiry is reached
*/
$expiry = 60; // One Hour
$cities = Person::remember($expiry)->distinct()->lists('city');
$states = Person::remember($expiry)->distinct()->lists('state');
I would love to hear some alternatives to this if you guys have one!
#ErikOnTheWeb
You could use array_column for this (it's a PHP 5.5 function but Laravel has a helper function that replicates the behavior, for the most part).
Something like this should suffice.
$tag_names = array_column($tags->toArray(), 'name');