Laravel 4: How to use an Accessor in a where-clause - php

Is it possible to use an Accessor for comparison in Laravel 4, for example:
class User extends Eloquent {
// define Accessor
public function getSpecialNameAttribute()
{
return 'Joda';
}
}
$User = User::where('gender','=','male')->where('specialName','=','Joda');
?

Yes, you can use it to filter query results:
User
::where('gender','=','male')
->get()
->filter(function($item) {
return $item->specialName === 'Luke';
});
(!) Note that filtering will be applied after quering DB, so in case of big data this solution will have performance issues.
For more details I've googled for you this Collections tutorial.
Also I suggest query scopes may be useful to complete your task in best way.

No, you cannot use it this way.
When you use:
$user = User::where('gender','=','male')->where('specialName','=','Joda')->get();
you will try to compare specialName column in database with Joda string.
You cannot use accessor here, because accessor may be very complicated and then Laravel would need to take all data from table in database (for example 100000 records) and calculate accessors for all of them to get for you only records you need (for example 1 record).
You can use accessor only when you have object instance, and you won't be able to use it when querying database.

Related

Advanced Laravel merged data/models - can it be done at model level?

We have a COMMON database and then tenant databases for each organization that uses our application. We have base values in the COMMON database for some tables e.g.
COMMON.widgets. Then in the tenant databases, IF a table called modified_widgets exists and has values, they are merged with the COMMON.widgets table.
Right now we are doing this in controllers along the lines of:
public function index(Request $request)
{
$widgets = Widget::where('active', '1')->orderBy('name')->get();
if(Schema::connection('tenant')->hasTable('modified_widgets')) {
$modified = ModifiedWidget::where('active', '1')->get();
$merged = $widgets->merge($modified);
$merged = array_values(array_sort($merged, function ($value) {
return $value['name'];
}));
return $merged;
}
return $countries;
}
As you can see, we have model for each table and this works OK. We get the expected results for GET requests like this from controllers, but we'd like to merge at the Laravel MODEL level if possible. That way id's are linked to the correct tables and such when populating forms with these values. The merge means the same id can exist in BOTH tables. We ALWAYS want to act on the merged data if any exists. So it seems like model level is the place for this, but we'll try any suggestions that help meet the need. Hope that all makes sense.
Can anyone help with this or does anyone have any ideas to try? We've played with overriding model constructors and such, but haven't quite been able to figure this out yet. Any thoughts are appreciated and TIA!
If you put this functionality in Widget model you will get 2x times of queries. You need to think about Widget as an instance, what I am trying to say is that current approach does 2 queries minimum and +1 if tenant has modified_widgets table. Now imagine you do this inside a model, each Widget instance will pull in, in a best case scenario its equivalent from different database, so for bunch of Widgets you will do 1 (->all())+n (n = number of ModifiedWidgets) queries - because each Widget instance will pull its own mirror if it exists, no eager load is possible.
You can improve your code with following:
$widgets = Widget::where('active', '1')->orderBy('name')->get();
if(Schema::connection('tenant')->hasTable('modified_widgets')) {
$modified = ModifiedWidget::where('active', '1')->whereIn('id', $widgets->pluck('id'))->get(); // remove whereIn if thats not the case
return $widgets->merge($modified)->unique()->sortBy('name');
}
return $widgets;
OK, here is what we came up with.
We now use a single model and the table names MUST be the same in both databases (setTable does not seem to work even though in exists in the Database/Eloquent/Model base source code - that may be why it's not documented). Anyway = just use a regular model and make sure the tables are identical (or at least the fields you are using are):
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
class Widget extends Model
{
}
Then we have a generic 'merge controller' where the model and optional sort are passed in the request (we hard coded the 'where' and key here, but they could be made dynamic too). NOTE THIS WILL NOT WORK WITH STATIC METHODS THAT CREATE NEW INSTANCES such as $model::all() so you need to use $model->get() in that case:
<?php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Config;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;
class MergeController extends Controller
{
public function index(Request $request)
{
//TODO: add some validations to ensure model is provided
$model = app("App\\Models\\{$request['model']}");
$sort = $request['sort'] ? $request['sort'] : 'id';
$src_collection = $model->where('active', '1')->orderBy('name')->get();
// we setup the tenants connection elsewhere, but use it here
if(Schema::connection('tenant')->hasTable($model->getTable())) {
$model->setConnection('tenant');
$tenant_collection = $model->get()->where('active', '1');
$src_collection = $src_collection->keyBy('id')->merge($tenant_collection->keyBy('id'))->sortBy('name');
}
return $src_collection;
}
}
If you dd($src_collection); before returning it it, you will see the connection is correct for each row (depending on data in the tables). If you update a row:
$test = $src_collection->find(2); // this is a row from the tenant db in our data
$test->name = 'Test';
$test->save();
$test2 = $src_collection->find(1); // this is a row from the tenant db in our data
$test2->name = 'Test2'; // this is a row from the COMMON db in our data
$test2->save();
dd($src_collection);
You will see the correct data is updated no matter which table the row(s) came from.
This results in each tenant being able to optionally override and/or add to base table data without effecting the base table data itself or other tenants while minimizing data duplication thus easing maintenance (obviously the table data and population is managed elsewhere just like any other table). If the tenant has no overrides then the base table data is returned. The merge and custom collection stuff have minimal documentation, so this took some time to figure out. Hope this helps someone else some day!

Laravel Eloquent HasMany / HasOne Additional On Clauses

Good morning,
Apologies if this has been ask before but we are unable to find any answer to an issue we are having.
We are working with a legacy database that is not owned by us (read-only) and are attempting to use Eloquent (Models) in Laravel to solve some common issues.
Is it possible to setup Eloquent's Eager-loading to create additional ON clauses to the HasMany / HasOne relationship builder?
Please see below of what we are trying to achieve without raw queries.
public function policy()
{
return $this->hasMany(Policy::class, 'Group', 'Group')
// This breaks as `on` isn't defined on Eloquent\Builder. Is this concept possible? Multiple on clauses
->on('Reference', 'Reference');
}
In our controller we have attempted the following which also fails.
Vehicle::with([
'policy' => function ($query) {
// Model isn't instantiated yet, but we need an additional on clause here
$query->on('Reference', 'Reference');
}
]);
Can the above be achieved or do we have to revert back to using raw queries?
Thank you in advance for any help.
You can use the Compoships package:
class Vehicle extends Model
{
use \Awobaz\Compoships\Compoships;
public function policy()
{
return $this->hasMany(Policy::class, ['Group', 'Reference'], ['Group', 'Reference']);
}
}
I am assuming the query already exists as raw SQL and what you are trying to achieve is to convert it to using eloquent. If that is the case you may find it quicker an deasier to use the built in raw query.

What's the advantage of using Laravel Eloquent Relationship queries?

So I'm trying to improve my queries by implementing eloquent relationships.
Let's say I have a threads table and each thread have replies
What I need is a JSON object of the information of threads with array of all the replies.
Currently, I can achieve what I want with this.
public function show($threadId){
$threads = ThreadView::find($threadId);
$threads->replies = ReplyView::where('threadId', $threadId)->get();
return response()->json($threads, 200);
}
With eloquent relationship, I can achieve the same result with something like this.
public function show($threadId) {
$threads= ThreadView::find($threadId);
$threads->replies= ThreadView::find($threadId)->Replies;
return response()->json($threads, 200);
}
Is there an advantage to using relationship? They both look the same to me.
Using Eloquent you can do this even shorter:
public function show($threadId) {
$threads = ThreadView::with('replies')->find($threadId);
return response()->json($threads, 200);
}
The with function will eager load relations without you having to write the query.
That is the advantage of Eloquent, it writes the queries for you. No need to create join queries or extra queries for you.
public function show($threadId) {
$threads= ThreadView::with('replies')->find($threadId);
return response()->json($threads, 200);
}
The main advantage is that using relationships like this, the first example does 2 selects (it grabs 100% of ThreadView then 100% of ReplyView), while the second example only does 1 query.
The second advantage is that Eloquent does a Really Good Job at lazy loading compared to others and it is much better to use if you are not an expert in SQL queries.
Ditching Eloquent models and using the DB Builder directly will be approximately 500x faster, and I find the code cleaner. That may be what you're looking for.
But if you use models, use the relationships!

Laravel 5 issue with wherePivot

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.

Check if belongsToMany relation exists - Laravel

Two of my tables (clients and products) have a ManyToMany relation using Laravel's blongToMany and a pivot table.
Now I want to check if a certain client has a certain product.
I could create a model to check in the pivot table but since Laravel does not require this model for the belongsToMany method I was wondering if there is another way to check if a certain relationship exists without having a model for the pivot table.
I think the official way to do this is to do:
$client = Client::find(1);
$exists = $client->products->contains($product_id);
It's somewhat wasteful in that it'll do the SELECT query, get all results into a Collection and then finally do a foreach over the Collection to find a model with the ID you pass in. However, it doesn't require modelling the pivot table.
If you don't like the wastefulness of that, you could do it yourself in SQL/Query Builder, which also wouldn't require modelling the table (nor would it require getting the Client model if you don't already have it for other purposes:
$exists = DB::table('client_product')
->whereClientId($client_id)
->whereProductId($product_id)
->count() > 0;
The question is quite old but this may help others looking for a solution:
$client = Client::find(1);
$exists = $client->products()->where('products.id', $productId)->exists();
No "wastefulness" as in #alexrussell's solution and the query is more efficient, too.
Alex's solution is working one, but it will load a Client model and all related Product models from DB into memory and only after that, it will check if the relationship exists.
A better Eloquent way to do that is to use whereHas() method.
1. You don't need to load client model, you can just use his ID.
2. You also don't need to load all products related to that client into memory, like Alex does.
3. One SQL query to DB.
$doesClientHaveProduct = Product::where('id', $productId)
->whereHas('clients', function($q) use($clientId) {
$q->where('id', $clientId);
})
->count();
Update: I did not take into account the usefulness of checking multiple relations, if that is the case then #deczo has a way better answer to this question. Running only one query to check for all relations is the desired solution.
/**
* Determine if a Client has a specific Product
* #param $clientId
* #param $productId
* #return bool
*/
public function clientHasProduct($clientId, $productId)
{
return ! is_null(
DB::table('client_product')
->where('client_id', $clientId)
->where('product_id', $productId)
->first()
);
}
You could put this in you User/Client model or you could have it in a ClientRepository and use that wherever you need it.
if ($this->clientRepository->clientHasProduct($clientId, $productId)
{
return 'Awesome';
}
But if you already have defined the belongsToMany relationship on a Client Eloquent model, you could do this, inside your Client model, instead:
return ! is_null(
$this->products()
->where('product_id', $productId)
->first()
);
#nielsiano's methods will work, but they will query DB for every user/product pair, which is a waste in my opinion.
If you don't want to load all the related models' data, then this is what I would do for a single user:
// User model
protected $productIds = null;
public function getProductsIdsAttribute()
{
if (is_null($this->productsIds) $this->loadProductsIds();
return $this->productsIds;
}
public function loadProductsIds()
{
$this->productsIds = DB::table($this->products()->getTable())
->where($this->products()->getForeignKey(), $this->getKey())
->lists($this->products()->getOtherKey());
return $this;
}
public function hasProduct($id)
{
return in_array($id, $this->productsIds);
}
Then you can simply do this:
$user = User::first();
$user->hasProduct($someId); // true / false
// or
Auth::user()->hasProduct($someId);
Only 1 query is executed, then you work with the array.
The easiest way would be using contains like #alexrussell suggested.
I think this is a matter of preference, so unless your app is quite big and requires a lot of optimization, you can choose what you find easier to work with.
Hello all) My solution for this problem: i created a own class, extended from Eloquent, and extend all my models from it. In this class i written this simple function:
function have($relation_name, $id) {
return (bool) $this->$relation_name()->where('id','=',$id)->count();
}
For make a check existing relation you must write something like:
if ($user->have('subscribes', 15)) {
// do some things
}
This way generates only a SELECT count(...) query without receiving real data from tables.
To check the existence of a relationship between 2 models, all we need is a single query against the pivot table without any joins.
You can achieve it using the built-in newPivotStatementForId method:
$exists = $client->products()->newPivotStatementForId($product->id)->exists();
use trait:
trait hasPivotTrait
{
public function hasPivot($relation, $model)
{
return (bool) $this->{$relation}()->wherePivot($model->getForeignKey(), $model->{$model->getKeyName()})->count();
}
}
.
if ($user->hasPivot('tags', $tag)){
// do some things...
}
This has time but maybe I can help someone
if($client->products()->find($product->id)){
exists!!
}
It should be noted that you must have the product and customer model, I hope it helps,

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