PHP Laravel Query Cloning Not Working as Expected - php

So I'm coming across an issue with QueryBuilder cloning. He's my situation, I need to run 3 separate queries, all based off a single "BaseQuery":
$baseQuery = $model->selectRaw("column")->whereNull("deleted_at");
$query1 = clone($baseQuery);
$query1Results = $query1->where("condition", "=", 0)->get();
$query2 = clone($baseQuery);
$query2Results = $query2->where("condition2", "=", 1)->get();
$query3 = clone($baseQuery);
$query3Results = $query3->where("condition3", "=", 0)->get();
By the time I get to $query3, it has 3 where statements. Substituting $query3 ... get() with $query3 ... ->toSql(); shows these results:
SELECT `column` FROM `models` WHERE `deleted_at` IS NULL AND `condition` = ? AND `condition2` = ? AND `condition3` = ?;
It seems that even though I am defining each $queryX as a clone of $baseQuery, the additional ->where() clause is being applied to each of the queries. I've tried doing the clone() before appending any of the ->where() clauses, but that doesn't have any affect.
Is there a way to clone() something and ensure that it creates a new instance? It looks like clone() isn't separating $baseQuery from $queryX, so the ->where()s are being applied to every subsequent copy, even though each should be a new query with only the ->whereNull() clause.
Another interesting point is that running
\Log::info($baseQuery == $queryX);
After each modification returns true (=== is false though)

You should use scopes here.
Local scopes allow you to define common sets of constraints that you may easily re-use throughout your application. For example, you may need to frequently retrieve all users that are considered "popular". To define a scope, simply prefix an Eloquent model method with scope
public function scopeBase($q)
{
return $q->selectRaw('column')->whereNull('deleted_at');
}
Then just do something like this:
$query1Results = $model->where('condition', 0)->base()->get();
$query2Results = $model->where('condition2', 1)->base()->get();
$query3Results = $model->where('condition3', 0)->base()->get();

Related

How to use one query for different selects in laravel?

I thought it would be a good idea to define a query and use it for several selects or counts later, but it does not work. The second select has both wheres in the sql statement:
$query = Pic::where('pics.user_id',$user->id);
if($cat) $query->where('cat',$cat);
if($year) $query->where('jahrprod',$year);
$zb = $query->select('pics.id','pics.title','pics.created_at')
->where('pics.id', '>', $pic->id)
->orderBy('pics.id')
->take(2)
->get()->reverse();
$za = $query->select('pics.id','pics.title','pics.created_at')
->where('pics.id', '<', $pic->id)
->orderBy('pics.id')
->take(13)
->get();
Query:
SELECT `pics`.`id`, `pics`.`title`, `pics`.`created_at`
FROM `pics`
WHERE `pics`.`user_id` = '3'
AND `pics`.`id` > '2180'
AND `pics`.`id` < '2180'
ORDER BY `pics`.`id` ASC, `pics`.`id` ASC
LIMIT 13
I tried to "pass it as reference" i.e. &$query->select... but "only variables can be passed as reference".
How can I use the query , or save it, and use it for both actions. Is it possible?
You are updating object state with the statements when you do $query->where(), so yeah, when you're doing a second select, all conditions from the first one are still there. Thats the reason why these lines work without any assignments:
if($cat) $query->where('cat',$cat);
if($year) $query->where('jahrprod',$year);
To achieve described behaviour you would need to create an query object copy:
$query = Pic::where('pics.user_id',$user->id);
if($cat) $query->where('cat',$cat);
if($year) $query->where('jahrprod',$year);
$queryClone = clone $query;
$zb = $query->select('pics.id','pics.title','pics.created_at')
->where('pics.id', '>', $pic->id)
->orderBy('pics.id')
->take(2)
->get()->reverse();
$za = $queryClone->select('pics.id','pics.title','pics.created_at')
->where('pics.id', '<', $pic->id)
->orderBy('pics.id')
->take(13)
->get();
Notice that mere assignment would not work here:
$queryClone = $query;
Because that would pass object reference and would result in the same behaviour as in your case. Clone creates a full object copy.
http://php.net/manual/en/language.oop5.cloning.php

Assign a query to variable to then perform two separate queries?

Is it possible to start an eloquent query, assign it to a variable then continue using the variable for two separate queries without them conflicting with one another. A simple example:
$students = $this->student
// more query stuff
->where('is_active', 1);
$bachelorStudents = $students
->where('course_id', 3)
->get();
$masterStudents = $students
->where('course_id', 4)
->get();
or would I need to do:
$bachelorStudents = $this->student
->where('course_id', 3)
->get();
$masterStudents = $this->student
->where('course_id', 4)
->get();
I always thought I could do the former, but some of my results appear to show I can't but I am open to believe that if you can do it then perhaps I'm doing something wrong.
When you're calling
$students = $this->student->where('is_active', 1);
you're creating a query builder object. Calling where*() on this object updates the object by adding given criteria. Therefore it's not possible to achieve what you want in your first code snippet, because when you call
$masterStudents = $students
->where('course_id', 4)
->get();
the query builder already contains where('course_id', 3) constraint added when you bachelorStudents.
Once you do that:
$students = $this->student->where('is_active', 1);
$stundents will contain a query builder with your where clause
If you do:
$bachelorStudents = $students->where('course_id', 3)->get();
You'll add another where clasuse to the $students builder, and this should work as you expect
But, when you do:
$masterStudents = $students->where('course_id', 4)->get();
You are adding another where clasuse to the same $students builder, thus resulting the query builder to be something like this:
$students->where('is_active', 1)
->where('course_id', 3)
->where('course_id', 4)
->get();
That probably isn't what you expect, because you have 2 where clauses with different course_id values
Think of $student as an object you modify everytime you add a clause, so you can use it for progressive query building, but remember that once you've added a clause to the query builder, the object is modified and the clause will be keept in the builder, so when you re-use the builder it will contain all the clasuses you previously added
Also, Rembember that when you need to apply some pre-defined filters to your query, in Laravel you should use query scopes
While everyone is explaining query builder and how it works, here's your answer.
1) Start off your query builder
$studentsQuery = $this->student
//Start a new query builder (optional)
->newQuery()
->where('is_active', 1);
2) Clone the initial query builder to our separate queries
$bachelorStudentsQuery = clone $studentsQuery;
$masterStudentsQuery = clone $studentsQuery;
3) Assign your where conditions and get the results
$bachelorStudentsResult = $bachelorStudentsQuery->where('course_id', 3)
->get();
$masterStudentsResult = $masterStudentsQuery->where('course_id',4)
->get();
Your use case is too simple for cloning.
It might help you DRY your code when lots of method chaining has been performed, especially when applying filters to queries.

How to get different queries (models) results with one statement? - laravel

Sorry if my title is confusing, not sure how to explain this within a line. Let's say I have a table with some columns and I have this
$model = Document::where('systemName', '=', $systemName)->where('ticketNumber', '=', ($nextTicketNumber))->get(); ticketNumber is unique where as there are quite a few systemNames
The above will get exactly what I want but I want more. I want an another array which will store all the rows under the same systemName. I know I can do this by doing
$allSystemNameModel = Document::where('systemName', '=', $systemName)
But is there a possible way to not having two variables and be easier?
No, you can't get both collections into one variable with one statement, however, you can create an array and store your results there:
$both = [];
$both['model'] = ...
$both['all'] = ...
UPDATE:
To avoid querying the database twice, you can use a first method that laravel provides us with.
$allSystemNameModel = Document::where('systemName', '=', $systemName);
$model = $allSystemNameModel->first(function ($doc) use ($nextTicketNumber) {
return $doc->ticketNumber == $nextTicketNumber;
});
$both['model'] = $model;
$both['all'] = $allSystemNameModel->all();
Note: Be sure to use use when working with php closures since $nextTicketNumber will be undefined otherwise.

Can we merge doctrine querybuilders and retrieve each ones' results ? is that a best practice?

I have a website where I populate the first page with objects of different nature (last posts, last recipes, last ingredients published). I have currently one querybuilder and then one query for each of them because I call ->getQuery()->getResult() on each of them.
Is there not a way to merge all those querybuilders before executing the query so as to retrieve an array of results made of the results of each of those querybuilders ?
Would that be a best practice ? How would we do it ?
EDIT: what I hoped we could do:
$recipesQueryBuilder = $this->getDoctrine->getRepository('Recipe')->createQueryBuilder('r');
$postsQueryBuilder = $this->getDoctrine->getRepository('Post')->createQueryBuilder('p');
$results = mergeQueryBuilder($recipesQueryBuilder, $postQueryBuilder)->getQuery()->getResult();
$recipes = $results['r'];
$posts = $results['p'];
I do this with many of our queries. I doubt there is a formal "best practice" for this kind of thing, however I can vouch for the fact that re-using builders does simplify the code. For example:
public function getListBuilder(User $user)
{
return $this->createQueryBuilder('l')->where('l.user = :user')->setParameter('user', $user)->orderBy('l.name');
}
I have a number of queries that re-use this base builder. For example:
public function countLists(User $user = null)
{
$qb = $this->getListBuilder($user);
return $qb->select('COUNT(l)')->getQuery()->getSingleScalarResult();
}
Likewise another method findActiveLists() changes the order to createdAt and generates a query with setMaxResults() specified.

Laravel method chaining a query through a function

Is it possible to conditionally chain methods in PHP / Laravel, or to pass method chains through functions?
I'd like to control a query in Laravel's query builder by setting up a base query first, then passing that to a function to have other methods chained on to the query. As a quick example:
$query = Model::whereFoo('bar');
if ($needFoo) {
$query = $query->has('foo');
}
$query = queryMethod($query);
function queryMethod($query) {
return $query->where('something', '<', 10);
}
$items = $query->get();
This seems to ignore everything between $query = Model::whereFoo('bar'); and $items = $query->get(); -- it doesn't seem to make any difference what happens to $query in between the two.
Is it possible / advisable to achieve this?
Edit: I've accepted the answer below as it answers the question I asked. My problem was actually unrelated. If it helps anyone: I had a rogue orWhere() call in the base query that was of course including unwanted results regardless of the other chained methods. That needed nesting inside an advanced where method as described in Laravel docs.
What you have should work, but you can simplify it:
$query = Model::whereFoo('bar');
if ($needFoo) $query->has('foo');
queryMethod($query);
function queryMethod($query) {
$query->where('something', '<', 10);
}
$items = $query->get();
Since objects in PHP are passed by reference, you'll always be dealing with the same instance.

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