I am trying to get a record from a posts database table using its id. I've been banging my head on the find() method for quite sometime now, confused as to why it wasn't working. Here is my query that looks correct to me but didn't work:
$post = Post::find($id);
$post->delete();
Reluctantly i did this:
$post = Post::where('id', $id);
$post->delete();
and surprisingly enough, it worked but I have no idea how.
I also know that unlike find(), where() is a query builder and so I could also use it like this:
Post::where('id', $id)->first()
Any ideas about the difference in the way the methods work?
Your code looks fine, but there are a couple of things to be aware of:
Post::find($id); acts upon the primary key, if you have set your primary key in your model to something other than id by doing:
protected $primaryKey = 'slug';
then find will search by that key instead.
Laravel also expects the id to be an integer, if you are using something other than an integer (such as a string) you need to set the incrementing property on your model to false:
public $incrementing = false;
Not Found Exceptions
Sometimes you may wish to throw an exception if a model is not found. This is particularly useful in routes or controllers. The findOrFail and firstOrFail methods will retrieve the first result of the query. However, if no result is found, a Illuminate\Database\Eloquent\ModelNotFoundException will be thrown:
$model = App\Flight::findOrFail(1);
$model = App\Flight::where('legs', '>', 100)->firstOrFail();
If the exception is not caught, a 404 HTTP response is automatically sent back to the user. It is not necessary to write explicit checks to return 404 responses when using these methods:
Route::get('/api/flights/{id}', function ($id) {
return App\Flight::findOrFail($id);
});
To add to craig_h's comment above (I currently don't have enough rep to add this as a comment to his answer, sorry), if your primary key is not an integer, you'll also want to tell your model what data type it is, by setting keyType at the top of the model definition.
public $keyType = 'string'
Eloquent understands any of the types defined in the castAttribute() function, which as of Laravel 5.4 are: int, float, string, bool, object, array, collection, date and timestamp.
This will ensure that your primary key is correctly cast into the equivalent PHP data type.
Related
I need to get an element from the database, but I can not get it by the FIND method, since FIND only finds it by the primaryKey and what I need is not by my primaryKey. So I did like this:
$user = Pac::find($request->pac_id);
$element = query()->where('med_cart', $user->pac_id)->get();
$element->med_obs = $request->med_obs;
$element->save(); // error
Now I need to save this element, however, I can not use the SAVE method, as I believe it is fully connected with FIND and FINDORFAIL (if anyone knows, explain to me which methods I can use the SAVE method).
How can I save them the way I did? Or is there some other way to do it?
Because I need to get the element with a data other than the primaryKey and then save it, then I can not use FIND or FINDORFAIL, I think.
The function ->find() returns an Eloquent Model instance and you can then call ->save() on the model instance.
You're using ->get() which returns a Collection.
To update your query (that may target one or more entries) just perform the update statement directly from the QueryBuilder by replacing ->get() with ->update(['med_obs' => $request->med_obs]).
Be aware that when doing this you are now using Fluent queries, instead of eloquent. This means that any logic you may have defined in the boot function of your model is not evaluated.
If you are certain that you only have a single result you can append ->first() to your query, which will return a Model of the first result that matches your ->where clause. You can then call ->save() on it:
$user = Pac::find($request->pac_id);
$element = query()->where('med_cart', $user->pac_id)->first();
$element->med_obs = $request->med_obs;
$element->save();
When searching for what should be a very basic and common test in Laravel, there seems to be much confusion on how to properly check weather or not a model exists and then do something with the model if it does. When searching through stackoverflow, laracasts, and the laravel documentation itself, it does not become anymore clear. If I for example run this query,
$restaurant = Restaurant::find($input["restaurant_id"]);
There are various stack overflow posts that would have me check the count(), use the exists() method which does not seem consistent, or use firstOrFail() which throws an exception. All I want to do is run a call like the one above, check if $restaurant is a valid model, and then do something if it is. There is no need for an exception in my case and I don't want to have to have to run the query again after using something like count() or exists(). The documentation has no useful information on this either which allows 4 different variable types to be returned without any mention of which case will trigger which return. Does anyone have a good handle on this topic?
Laravel checking if record exists
Eloquent ->first() if ->exists()
https://laravel.com/api/5.2/Illuminate/Database/Eloquent/Builder.html#method_find
You don't need to run any additional queries. If the record does not exist, find() will return null. You can just use a simple if to check:
if($restaurant = Restaurant::find($input["restaurant_id"]) {
// Do stuff to $restaurant here
}
You can also use
$restaurant = Restaurant::findOrFail($input["restaurant_id"]);
Sometimes you may wish to throw an exception if a model is not found. This is particularly useful in routes or controllers. The findOrFail and firstOrFail methods will retrieve the first result of the query. However, if no result is found, a Illuminate\Database\Eloquent\ModelNotFoundException will be thrown:
From: https://laravel.com/docs/5.1/eloquent
Its very clear in laravel docs about your question, find(),first(),get(), all return null if the model not exist,
$model = Restaurant::find(111); // or
$model = Restaurant::where('id',111)->first();
if(!$model){ //if model not exist, it means the model variable is null
}
I'm trying to get a single column value from the first result of a Model's belongsToMany relationship query, as i'm returning the ->first() result of the relationship I was hoping $code->reward->title would work but it doesn't.
I get an Relationship method must return an object of type Illuminate\Database\Eloquent\Relations\Relation error
What I'm trying to do is the get the title of the current reward that is linked to a specific code - the code_reward pivot table has a valid_from and expires_at date as the reward linked to a code will change as time goes by, hence the need to get the currently active reward for that code.
Here's my code:
Model: Code
public function rewards()
{
return $this->belongsToMany('App\Reward')->withPivot('valid_from', 'expires_at')->withTimestamps();
}
public function reward()
{
$now = Carbon::now();
return $this->rewards()
->wherePivot('valid_from', '<', $now)
->wherePivot('expires_at', '>', $now)
->first();
}
Controller: CodeController
public function index()
{
$codes = Code::all();
return view('codes/index')->with('codes', $codes);
}
View: Codes/index
#foreach ($codes as $code)
{{$code->id}}
{{$code->reward->title}}
#endforeach
Any help is really appreciated!
Update
Unfortunately both suggestions below ($code->reward()->title and getRewardAttribute() return an Trying to get property of non-object error.
If I remove ->first() from the Code->reward() method and replace $code->reward->title with $code->reward->first() in the view it echoes out the whole reward model as json, however $code->reward->first()->title still returns the Trying to get property of non-object error
Update 2
If I do {{dd($code->reward->title)}} in the view I get the reward title but if I just do {{$code->reward->title}}, I don't!
AND the $code->reward->title works as expected in a #Show view, so could it be that the collection of codes supplied by the controller's #index method isn't passing the necessary data or not passing it in a necessary format??
SOLVED
The issue was caused by one of the $code->rewards in the foreach loop in the index view returning null! The first one didn't, hence the dd() working but as soon as the loop hit a null it crashed.
Once I wiped and refreshed the db (and made sure my seeds where adding only valid data!) it worked. Doing {{$code->reward ? $code->reward->title : ''}} fixed the issue. Grrr.
Your statement is failing because $code->reward->title tells Laravel that you have defined a relationship on your Code model in a method called reward(). However, your relationship is actually defined in the method rewards(). Instead, reward() is a custom method on the model that you have made up. Calling it as a method and not a relation is the quickest way to get what you want.
{{$code->reward()->title}}
As #andrewtweber points out below, you could also make your custom reward() method into an attribute accessor. To do that, just rename the function to getRewardAttribute() and then you can call it in your view like you originally did.
Alternatively, you could get rid of that reward() method entirely and move all of that logic to the controller, where it probably makes more sense. You'd have to use constrained eager loading to pull that off. So in your controller you'd have something like this:
$codes = App\Code::with(['rewards' => function ($query) {
$query->wherePivot('valid_from', '<', $now)
->wherePivot('expires_at', '>', $now);
])->get();
Of course, this would return all of your filtered codes. This is because you cannot apply a sql limit inside a nested eager relationship as outlined here. So in your view, you would then have to do something like this:
{{$code->rewards->first()->title}}
However, it will be simpler to go with my first solution, so that's entirely up to you.
Try to set this method in Code Model, because query builder treats valid_from and expired_at as string, not date?
public function getDates()
{
return ['valid_from','expired_at'];
}
I am working with Laravel 5 and I am having issue getting ->wherePivot() to work on a Many-to-Many relationship. When I dd() the SQL it looks like Eloquent is looking for records in the pivot table with a `pose_state`.`pose_id` is null`.
I am hoping it is a simple error and not a bug. Any ideas are appreciated.
Database Structure
pose
id
name
type
state
id
name
machine_name
pose_state
pose_id
state_id
status
Models
Pose
<?php namespace App;
use DB;
use App\State;
use Illuminate\Database\Eloquent\Model;
class Pose extends Model {
public function states()
{
return $this->belongsToMany('App\State')
->withPivot('status_id')
->withTimestamps();
}
public function scopeWithPendingReviews()
{
return $this->states()
->wherePivot('status_id',10);
}
}
State
<?php namespace App;
use Illuminate\Database\Eloquent\Model;
class State extends Model {
public function poses()
{
return $this->belongsToMany('Pose')
->withPivot('status_id')
->withTimestamps();
}
}
PosesController function
public function listPosesForReview(){
$poses = Pose::withPendingReviews()->get();
dd($poses->toArray() );
}
SQL
select
`states`.*, `pose_state`.`pose_id` as `pivot_pose_id`,
`pose_state`.`state_id` as `pivot_state_id`,
`pose_state`.`status_id` as `pivot_status_id`,
`pose_state`.`created_at` as `pivot_created_at`,
`pose_state`.`updated_at` as `pivot_updated_at`
from
`states` inner join `pose_state` on `states`.`id` = `pose_state`.`state_id`
where
`pose_state`.`pose_id` is null and `pose_state`.`status_id` = ?
EDIT
When I updated my code to removing the scope it worked. Thanks #Deefour for putting me on the right path! Maybe scope has something else to that I am missing.
public function pendingReviews()
{
return $this->states()
->wherePivot('status_id','=', 10);
}
YET ANOTHER EDIT
I finally got this to work. The solution above was giving me duplicate entries. No idea why this works, but it does, so I will stick with it.
public function scopeWithStatusCode($query, $tag)
{
$query->with(['states' => function($q) use ($tag)
{
$q->wherePivot('status_id','=', $tag);
}])
->whereHas('states',function($q) use ($tag)
{
$q->where('status_id', $tag);
});
}
I think your implementation of scopeWithPendingReviews() is an abuse of the intended use of scopes.
A scope should be thought of as a reusable set of conditions to append to an existing query, even if that query is simply
SomeModel::newQuery()
The idea is that a pre-existing query would be further refined (read: 'scoped') by the conditions within the scope method, not to generate a new query, and definitely not to generate a new query based on an associated model.
By default, the first and only argument passed to a scope method is the query builder instance itself.
Your scope implementation on your Pose model was really a query against the states table as soon as you did this
$this->states()
This is why your SQL appears as it does. It's also a clear indicator you're misusing scopes. A scope might instead look like this
public function scopeWithPendingReviews($query) {
$query->join('pose_state', 'poses.id', '=', 'pose_state.pose.id')
->where('status_id', 10);
}
Unlike your new pendingReviews() method which is returning a query based on the State model, this scope will refine a query on the Pose model.
Now you can use your scope as you originally intended.
$poses = Pose::withPendingReviews();
which could be translated into the more verbose
$poses = Pose::newQuery()->withPendingReviews();
Notice also the scope above doesn't return a value. It's accepting the existing query builder object and adding onto it.
The other answer to this question is filled with misinformation.
You cannot use wherePivot() as is claims.
Your use of withTimestamps() is not at all related to your problem
You don't have to do any "custom work" to get timestamps working. Adding the withTimestamps() call as you did is all that is needed. Just make sure you have a created_at and updated_at column in your join table.
I think that your implementation of scopes is fine, the problem I see is just a typo. Your schema shows that the field is called status but your where condition is referring to a status_id
Try:
->wherePivot('status', 10);
Also, the withTimestamps() method is causing issues. You don't have timestamps in your schema for the pivot (as I can see) so you shouldn't be putting these in the your relation definitions as it's trying to fetch the timestamps relating to when the relation was created/updated. You can do this if you set up your pivot table schema to have the timestamp fields, but I think you'll have to do some custom work to get the timestamps to save properly.
This worked for me (Laravel 5.3):
$task = App\Models\PricingTask::find(1);
$task->products()->wherePivot('taggable_type', 'product')->get();
You can also have this problem (return no results) if the column you are using in wherePivot hasn't been added to withPivot.
I am currently learning Symfony and Doctrine by reading the docs.
I don't understand the difference between find and findOneById. I tried to use them both in this simple example and it looks they do the same thing to me.
$product = $this->getDoctrine()
->getRepository('AcmeStoreBundle:ProductEntity')
->findOneById($id);
Are they really the same thing or there is some difference? And where I can find the detailed documentation for all these methods?
In your case, they happen to do the same thing. Looking at this example, you'll notice that find() looks for the field named after the primary key. findOneBy<Field>() will explicitly use the field in the name of the method, even if it's not the primary key, and will return the first record. So, in the end, if the primary key is indeed named id, then both will do the same thing.
// query by the primary key (usually "id")
$product = $repository->find($id);
// dynamic method names to find based on a column value
$product = $repository->findOneById($id);
$product = $repository->findOneByName('foo');
There is an API here I don't think there is any difference: the two methods, when call the way you call them, do this:
return $this->_em->getUnitOfWork()->getEntityPersister($this->_entityName)->load($id);
But find will be quicker and far quicker in some cases, because it doesn't use the __call magic method, and because find() checks a map of the current unit of work before whereas load() doesn't (see the #todo):
/**
* Loads an entity by a list of field criteria.
* ...
*
* #todo Check identity map? loadById method? Try to guess whether $criteria is the id?
*/
public function load(array $criteria, $entity = null, $assoc = null, array $hints = array(), $lockMode = 0)
So prefer find(), findOneById() is just a less efficient method to do the same thing.
In fact, is not the same thing.
Think about it. If you call "findBy()" you assume you'll receive a collection of entities ( 0, 1 or more than one ). So, to get all results, you'll need to iterate ArrayCollection or just get first ( $result->first() ).
If your query is by a unique key ( As this case ), you can just get unique entity by calling "getOneById()" and you will receive the entity as result.
/**
* Retrieving Product with 'findOneBy'
*/
$product = $this->getDoctrine()
->getRepository('AcmeStoreBundle:ProductEntity')
->findOneById($id);
/**
* Retrieving Product with 'findBy'
*/
$product = $this->getDoctrine()
->getRepository('AcmeStoreBundle:ProductEntity')
->findById($id)
->first();
Semantically, the first one it the best.
*TIP
Entity should be called just Product.
Why? Because is under "/Entity" folder ( Almost, should... ), and namespace will contain info about "What is exactly Product"
// query by the primary key (usually "id")
$product = $repository->find($id);
// dynamic method names to find based on a column value
$product = $repository->findOneById($id);
// $foo is any name which you want to find from database
$product = $repository->findOneByName($foo);
It calls the same method in the end.
findByKey('value')
Is basically the same as
findBy(array('key' => 'value'))
Where key is the property of the entity and value is the value of the property.
findById($id)
Is a special case of the above. And so is
find($id)
All of these methods execute the same query in the end. However, there is a difference in
findBy()
and
findOneBy()
Where findOneBy() only returns a single result and findBy will return all the results satisfying the demands.
However, in general it is considered good practice to use DQL queries instead. Consider lazy loading, array hydration, prepared statements, etc.
This is an interesting article on the topic:
Some Doctrine 2 Best Practices
Is the same thing, but I prefer the findOneBy method. It's more clear.