I have a query in which I have eagar loaded two models using with function like this:
ModelA::with(['relationB', 'relationC.relationC.A'])->where(condition)->get();
So, ModelA has two relations like this:
public function B(){ return $this->blongsTo(B::class);}
public function C(){ return $this->blongsTo(C::class);}
Now, my requirement is that I want to add a condition in B() function like this:
public function C() {
if($this->B->status) {
return $this->blongsTo(C::class)->withTrashed();
}
return $this->blongsTo(C::class);
}
But it return null on line this statement:
if($this->B->status)
Here is the error message
Trying to get property 'status' of non-object
My ultimate requirement is that using one relation function I want to fetch deleted records and non deleted based on the condition, but somehow it is not working.
My laravel application version is 7.30.4.
A relational function (such as your public function C()) works a bit of magic under the hood. This is because really it is designed to be called in a query way like you show already with the ::with(['relationB', ...]).
However, because of this, if you were to eager load C, then $this is not yet loaded as the full model, and therefore B is not defined (this is assuming that modelA always has a B relation). If you were to dd($this) while performing your query, you'd see that the result would be a model without any attributes.
Getting this to work from within a relational function (with the goal of eager loading) is very difficult. You're probably better off doing the logic elsewhere, with a second query for example. This is because within the relational function, there is no way to know who or what the potential target is. However, if you only use it after modelA is loaded, then it works without issues.
You can do some things with a whereHas, but then you'd still have to do 2 queries, or you can try and see if you can get it done with an SQL IF statement, but that will not result in a relation.
Related
I'm facing a weird problem which only happen in the production server (It's 100% normal in my local). I'm using Laravel 8, and have a model named Student. Inside the model, I created several scope methods like this:
public function scopeWhereAlreadySubmitData($query)
{
return $query->where('status_data_id', '!=', 1);
}
public function scopeWhereAlreadySubmitDocument($query)
{
return $query->where('status_document_id', '!=', 1);
}
Then I use the methods above in an AJAX controller to chain it with count method. Something like:
public function getAggregates()
{
$student = Student::with(['something', 'somethingElse']);
$count_student_already_submit_data = $student->whereAlreadySubmitData()->count();
$count_student_already_submit_document = $student->whereAlreadySubmitDocument()->count();
return compact('count_student_already_submit_data', 'count_student_already_submit_document');
}
Here's is where the weird thing happens: while the controller above produce the correct value in my local, in production count_student_already_submit_data has a correct value but count_student_already_submit_document has zero value. Seeing at the database directly, count_student_already_submit_document should have value more than zero as there are many records has status_document_id not equals to 1.
I've also tried to use the scopeWhereAlreadySubmitDocument method in tinker. Both in local and production, it shows the correct value, not just zero.
Another thing to note is that Student model actually had 4 scope methods like the above, not just 2. 3 of them is working correctly, and only 1 is not. Plus, there's another controller using all the scope methods above and all of them are showing the correct value.
Have you ever face such thing? What could be the problem behind this? Your input is appreciated.
Turns out this is because the query builder is effected by the given chain. The weird thing I mentioned about "local vs production" is likely doesn't gets noticed in the local because its only has a few records. I should've use clone() when chaining the builder. See the topic below for more information.
Laravel query builder - re-use query with amended where statement
So, in order to check the existence of a relationship on a model, we use the has function on the relationship like model1->has('relationship1').
While it is possible to supply the model1->with() function with an array of relations to eager load them all, both has and whereHas functions do not accept arrays as parameters. How to check for the existence of multiple relationships?
Right now, I am running multiple has functions on the same model (The relations are not nested):
model1->has('relationship1')
->has('relationship2')
->has('relationship3')
But that is tedious and error-prone. Solution anyone?
There unfortunately isn't a way to pass an array of relationships to has() or whereHas(), but you can use a QueryScope instead. On your Model, define the following:
public function scopeCheckRelationships($query){
return $query->has("relationship1")->has("relationship2")->has("relationship3");
}
Then, when querying your Model in a Controller, simply run:
$result = Model::checkRelationships()->get();
The function name to use a Scope is the name of the function, minus the word scope, so scopeCheckRelationships() is used as checkRelationships().
Also, it's actually possible to pass the relationships you want to query as a param:
public function scopeCheckRelationships($query, $relationships = []){
foreach($relationships AS $relationship){
$query->has($relationship);
// Might need to be `$query = $query->has(...);`, but I don't think so.
}
return $query;
}
...
$result = Model::checkRelationships(["relationship1", "relationship2", "relationship3"])->get();
In case you need this to be dynamic.
Here's the documentation for Query Scopes if you need more info: https://laravel.com/docs/5.8/eloquent#query-scopes
I created a queryScope
public function scopeCtmpActive($query)
{
return $query->where('ctmp_active', 'y');
}
Then I replace following line
$customtemplates_collection = Auth::user()->customtemplates->where('ctmp_active', 'y')->sortByDesc('ctmp_id');
with
$customtemplates_collection = Auth::user()->customtemplates->ctmpActive()->sortByDesc('ctmp_id');
And I am getting following FatalErrorException
Call to undefined method Illuminate\Database\Eloquent\Collection::ctmpActive()
How am I suppose to use a query exception with a relationship?
As the name implies, "query" scopes are for reusable, common "query" constraints.
$customtemplates_collection = Auth::user()->customtemplates;
This returns a collection. You are getting all "customtemplates" that belong to the authenticated user. Then, Laravel is nice in that the Collection class allows for a nice way to filter out results, which is why the next part works:
$customtemplates_collection = Auth::user()->customtemplates->where('ctmp_active', 'y');
You are using PHP. Not MySQL. To emphasize, you are getting every single "customtemplates" that belongs to the user, and then using (PHP) Laravel Collection's where method to go through each one and filter out the results. You are not adding a where clause to the query. That's why the above works.
However, query scopes are for query constraints so they need to happen during the query, not after. What you probably want is something like this:
$customtemplates_collection = Auth::user()->customtemplates()->ctmpActive()->orderBy('ctmp_id', 'desc')->get();
When you add the paranthesis after customtemplates(), you are invoking the customtemplates method. In this case, I'm assuming it's a HasMany relationship so it'll return a HasMany instance. Then basically, it uses PHP's magic method (__call) to build the query builder so each method after that is essentially prepping the database query. Then, when you're finished building the query, you call get to fetch the results.
I have a Batch model, which hasMany Results and belongsTo a Project. The current status of a batch is based on the status of its most recent Result. So, in my batch model I have this:
public function allForProject($pid)
{
$batches = $this
->with(static::$relatedObjects)
->with('current_status')
->where('project_id', '=', $pid)
->get();
return $batches;
}
public function current_status()
{
return $this
->belongsToMany('BehatEditor\Models\Result')
->orderBy('created_at', 'DESC')
->limit(1)
;
}
...So by saying "->with('current_status')" I am trying to eager load only the most recent result for that batch - there may be thousands of them per batch that I do not want to return to the front end.
Now, this doesn't break, but the "limit(1)" actually seems to limit the number of Batches that get returned with a Result. Even though each one of my Batches has 2 results with my test data, when I use limit(1) only one of them comes back with any data. When I use limit(2), only 2 batches come back with a single current_status record (desired) but the rest have an empty array for current_status.
This is a Silex project using Eloquent as an ORM, so Laravel specific methods won't work.
Any help is much appreciated!
UPDATE:
It looks like Eloquent just doesn't support this. see http://irclogs.julien-c.fr/2013-12-19/01:48#log-52b25061a599aafb54008650. I would like to update my question to be how can I cleanly add the raw SQL I need to my query? Can I supply my own method that holds only the SQL needed, or do I need to replace all ORM usage in allForProject()?
Instead of ->limit(1), use ->first().
Update: Misread what you said, this should work.
I'm working in Laravel 4, and I have a Child model with multiple EducationProfiles:
class Child extends EloquentVersioned
{
public function educationProfiles()
{
return $this->hasMany('EducationProfile');
}
}
If I wanted to get all the EducationProfiles for each kid under age 10 it would be easy:
Child::where('date_of_birth','>','2004-03-27')->with('educationProfiles')->all();
But say (as I do) that I would like to use with() to grab a calculated value for the Education Profiles of each of those kids, something like:
SELECT `education_profiles`.`child_id`, GROUP_CONCAT(`education_profiles`.`district`) as `district_list`
In theory with() only works with relationships, so do I have any options for associating the district_list fields to my Child models?
EDIT: Actually, I was wondering whether with('educationProfiles') generates SQL equivalent to:
EducationProfile::whereIn('id',array(1,2,3,4))
or whether it's actually equivalent to
DB::table('education_profiles')->whereIn('id',array(1,2,3,4))
The reason I ask is that in the former I'm getting models, if it's the latter I'm getting unmodeled data, and thus I can probably mess it up as much as I want. I assume with() generates an additional set models, though. Anybody care to correct or confirm?
Ok, I think I've cracked this nut. No, it is NOT possible to eager load arbitrary queries. However, the tools have been provided by the Fluent query builder to make it relatively easy to replicate eager loading manually.
First, we leverage the original query:
$query = Child::where('date_of_birth','>','2004-03-27')->with('educationProfiles');
$children = $query->get();
$eagerIds = $query->lists('id');
Next, use the $eagerIds to filterDB::table('education_profile') in the same way that with('educationProfiles') would filter EducationProfile::...
$query2 = DB::table('education_profile')->whereIn('child_id',$eagerIds)->select('child_id', 'GROUP_CONCAT(`education_profiles`.`district`) as `district_list`')->groupBy('child_id');
$educationProfiles = $query2->lists('district_list','child_id');
Now we can iterate through $children and just look up the $educationProfiles[$children->id] values for each entry.
Ok, yes, it's an obvious construction, but I haven't seen it laid out explicitly anywhere before as a means of eager loading arbitrary calculations.
You can add a where clause to your hasMany() call like this:
public function educationProfilesUnderTen() {
$ten_years_ago = (new DateTime('10 years ago'))->format('Y-m-d');
return $this->hasMany('EducationProfile')->where('date_of_birth', '>', $ten_years_ago)
}