I have two models: item and faq. The are in a belongsToMany with each other with a correctly created join table: item_faq (singular of both). My join table has an additional field on it for order.
In my view I get all the faq's and if they have a pivot table record I output "checked" on a checkbox. I also have drag and drop ordering on the checkbox list and that works well.
A few code notes:
// ITEMS MODEL
public function faqs(){
return $this->belongsToMany('App\Faq');
}
// FAQ MODEL
public function items(){
return $this->belongsToMany('App\Item');
}
public function hasItem($item) {
$items = $this->items->lists('id');
return in_array($item, $items);
}
Schema of join table:
item_id
faq_id
order
timestamps
My issue is that they faq's don't load sorted by the order column on the pivot table.
I am using a very simple:
$faqs = \App\Faq::with('items')->get();
To retrieve the FAQ's and this works at getting all the faq's and if they are related, it checks the checkbox.
How can I order these by the order column on the join table?
Have a look at Eager Load Constraints and I think it will help provide a solution. From the docs:
Of course, eager loading Closures aren't limited to "constraints". You may also apply orders:
$users = User::with(['posts' => function($query) {
$query->orderBy('created_at', 'desc');
}])->get();
Related
I have 4 table categories, initiatives, a pivot table for the "Many To Many" relationship category_initiative and initiativegroup table related with initiatives table with initiatives.initiativesgroup_id with one to many relation.
With pure sql I retrive the information I need with:
SELECT categories.id, categories.description, initiatives.id, initiatives.description, initiativegroups.group
FROM categories
LEFT JOIN category_initiative ON categories.id = category_initiative.category_id
LEFT JOIN initiatives ON category_initiative.initiative_id = initiatives.id
LEFT JOIN initiativegroups ON initiatives.initiativegroup_id = initiativegroups.id
WHERE categories.id = '40'
How can I use eloquent model to achieve same results?
Since you have such a specific query touching multiple tables, one possibility is to use query builder. That would preserve the precision of the query, retrieving only the data you specifically need. That would look something like this:
$categories = DB::table('categories')
->select([
'categories.id',
'categories.description',
'initiatives.id',
'initiatives.description',
'initiativegroups.group',
])
->leftJoin('category_initiative', 'categories.id', '=', 'category_initiative.category_id')
->leftJoin('initiatives', 'category_initiative.initiative_id', '=', 'initiatives.id')
->leftJoin('initiativegroups', 'initiatives.initiativegroup_id', '=', 'initiativegroups.id')
->where('categories.id', '=', 40)
->get();
In your models define the relationships:
Category.php model
public function initiatives()
{
return $this->belongsToMany('App\Initiative');
}
Initiative.php model (If has many categories change to belongs to many)
public function category()
{
return $this->belongsTo('App\Category');
}
Then maybe change your initiativegroup -> groups table, and then create a pivot table called group_initiative. Create model for group. Group.php and define the relationship:
public function initiatives()
{
return $this->belongsToMany('App\Initiative');
}
Then you can also add the following relationship definition to the Initiative.php model
public function group()
{
return $this->belongsTo('App\Group');
}
That should get you started.
for the record..
with my original relationship, but changing table name as alex suggest, in my controller:
$inits = Category::with('initiative.group')->find($id_cat);
simple and clean
I have found this: Get Specific Columns Using “With()” Function in Laravel Eloquent
but nothing from there did not help.
I have users table, columns: id , name , supplier_id. Table suppliers with columns: id, name.
When I call relation from Model or use eager constraints, relation is empty. When I comment(remove) constraint select(['id']) - results are present, but with all users fields.
$query = Supplier::with(['test_staff_id_only' => function ($query) {
//$query->where('id',8); // works only for testing https://laravel.com/docs/6.x/eloquent-relationships#constraining-eager-loads
// option 1
$query->select(['id']); // not working , no results in // "test_staff_id_only": []
// option 2
//$query->raw('select id from users'); // results with all fields from users table
}])->first();
return $query;
In Supplier model:
public function test_staff_id_only(){
return $this->hasMany(User::class,'supplier_id','id')
//option 3 - if enabled, no results in this relation
->select(['id']);// also tried: ->selectRaw('users.id as uid from users') and ->select('users.id')
}
How can I select only id from users?
in you relation remove select(['id'])
public function test_staff_id_only(){
return $this->hasMany(User::class,'supplier_id','id');
}
now in your code:
$query = Supplier::with(['test_staff_id_only:id,supplier_id'])->first();
There's a pretty simple answer actually. Define your relationship as:
public function users(){
return $this->hasMany(User::class, 'supplier_id', 'id');
}
Now, if you call Supplier::with('users')->get(), you'll get a list of all suppliers with their users, which is close, but a bit bloated. To limit the columns returned in the relationship, use the : modifier:
$suppliersWithUserIds = Supplier::with('users:id')->get();
Now, you will have a list of Supplier models, and each $supplier->users value will only contain the ID.
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've found the concept and meaning behind these methods to be a little confusing, is it possible for somebody to explain to me what the difference between has and with is, in the context of an example (if possible)?
With
with() is for eager loading. That basically means, along the main model, Laravel will preload the relationship(s) you specify. This is especially helpful if you have a collection of models and you want to load a relation for all of them. Because with eager loading you run only one additional DB query instead of one for every model in the collection.
Example:
User > hasMany > Post
$users = User::with('posts')->get();
foreach($users as $user){
$users->posts; // posts is already loaded and no additional DB query is run
}
Has
has() is to filter the selecting model based on a relationship. So it acts very similarly to a normal WHERE condition. If you just use has('relation') that means you only want to get the models that have at least one related model in this relation.
Example:
User > hasMany > Post
$users = User::has('posts')->get();
// only users that have at least one post are contained in the collection
WhereHas
whereHas() works basically the same as has() but allows you to specify additional filters for the related model to check.
Example:
User > hasMany > Post
$users = User::whereHas('posts', function($q){
$q->where('created_at', '>=', '2015-01-01 00:00:00');
})->get();
// only users that have posts from 2015 on forward are returned
The documentation has already explained the usage, so I will use SQL to explain the methods.
Example:
Assuming there is an Order (orders) has many OrderItem (order_items) and you already built the relationship between them:
// App\Models\Order:
public function orderItems() {
return $this->hasMany('App\Models\OrderItem', 'order_id', 'id');
}
These three methods are all based on a relationship.
with
Result: with() return the model object and its related results.
Advantage: It is eager-loading which can prevent the N+1 problem.
When you are using the following Eloquent Builder:
Order::with('orderItems')->get();
Laravel change this code to only two SQL:
// get all orders:
SELECT * FROM orders;
// get the order_items based on the orders' id above
SELECT * FROM order_items WHERE order_items.order_id IN (1,2,3,4...);
And then Laravel merges the results of the second SQL query with the results of the first SQL by foreign key, finally returning the collection results.
So if you selected columns without the foreign_key in a closure, the relationship result will be empty:
Order::with(['orderItems' => function($query) {
// $query->sum('quantity');
$query->select('quantity'); // without `order_id`
}
])->get();
#=> result:
[{ id: 1,
code: '00001',
orderItems: [], // <== is empty
},{
id: 2,
code: '00002',
orderItems: [], // <== is empty
}...
}]
has
Has will return the model's object when its relationship is not empty.
Order::has('orderItems')->get();
Laravel changes this code to one SQL query:
select * from `orders` where exists (
select * from `order_items` where `orders`.`id` = `order_items`.`order_id`
)
whereHas
The methods whereHas and orWhereHas put where conditions on your has queries. These methods allow you to add customized constraints to a relationship constraint.
Order::whereHas('orderItems', function($query) {
$query->where('status', 1);
})->get();
Laravel changes this code to one SQL query:
select * from `orders` where exists (
select *
from `order_items`
where `orders`.`id` = `order_items`.`order_id` and `status` = 1
)
Scenario
An alert can have many criterias, and many criterias can have my alerts.
A user is assigned to a criteria. When a user views all of their criteria, I want it to show the sum of how many matching alerts there are (stored in the pivot table). The relationship uses a pivot table structured as:
So for example, I can access the alert and criteria data, and it should also tell me that for criteria_id = 73, there is one alert match id_2.
So the Eloquent formula is currently:
public function getIndex()
{
$alerts = Criteria::with('coordinate', 'alerts')
->where('user_id', '=', Auth::user()->id)
->get();
$this->layout->content = View::make('users.alert.index',
array('alerts' => $alerts));
}
Relationship within Alert model
public function criterias()
{
return $this->belongsToMany('Criteria')->withTimestamps();
}
Relationship within Criteria model
public function alerts()
{
return $this->belongsToMany('Alert')->withTimestamps();
}
If you require any further information, please let me know. Many thanks for your help.
I solved my question by using #JarekTkaczyk's example above.
Getting count from pivot table in laravel eloquent