[Proposal] $query->whereFieldExists

[alexandre-butynski]

Sometimes, I have to use this syntax :

User::whereRaw(array('programs_ids.'.$program_id => array('$exists' => true)));

It could be better if it was :

User::whereExists('programs_ids.'.$program_id);

But a whereExists() method already exists in Laravel. It corresponds to the WHERE EXISTS SQL operator, wich have no sens in the MongodDB context, am I right ? It could be good to overwrite the initial method with an other one, matching the $exists MongoDB operator like in the case above but it's impossible because the arguments are not the same (the initial method need a Closure as first argument).

We could have a whereFieldExists() method with an implementation like that :

public function whereFieldExists($column, $exists = true, $boolean = 'and')
{
    return $this->whereRaw(array($column => array('$exists' => $exists)), array(), $boolean);
}

public function whereFieldNotExists($column, $boolean = 'and')
{
    return $this->whereFieldExists($column, false, $boolean);
}

After tests and writing this I'm not completely sure that this syntax is really great... What do you think about ? this question is more general because we could have also whereType or whereAll. I could work on this in the next days.

[jenssegers]

I could just overwrite the whereExists method, or does this mean something different in MySQL?

[alexandre-butynski]

Yes, it means something different (http://dev.mysql.com/doc/refman/4.1/en/exists-and-not-exists-subqueries.html) and a method already exists. We can't override it because the first argument has to be a Closure.

[jenssegers]

And I guess whereNotNull does not give the same results.

[alexandre-butynski]

In fact, whereNotNull give something very close that {$exists: true}. The only difference is were an index exists but has a null value... but it doesn't matter in my use case. It look like a side effect but, in my particular case, it does the job for the moment. Thanks to lead me to this solution.

In a more general discussion, what do you think about writing custom methods for specific MongoDB operators ($type, $exists, $all, $size...) ?

[jenssegers]

I will take a look at it, should not be that hard I guess.

[alexandre-butynski]

Ok, ask if you need help.

[jenssegers]

Check out https://github.com/jenssegers/Laravel-MongoDB#mongodb-specific-operators

[alexandre-butynski]

Great !

[NominationP]

How to solve this

[NominationP]

$query->whereExists(function($que){
$que->select(1)->from('bargain_coupons')->whereRaw('bargain_coupons.shop_id=id');
});

--! help