Laravel Eloquent - distinct() and count() not working properly together

Question

The following should work

$ad->getcodes()->distinct()->count('pid');

A more generic answer that would have saved me time, and hopefully others:

Does not work (returns count of all rows):

DB::table('users')
            ->select('first_name')
            ->distinct()
            ->count();

The fix:

DB::table('users')
            ->distinct()
            ->count('first_name');

Anyone else come across this post, and not finding the other suggestions to work?

Depending on the specific query, a different approach may be needed. In my case, I needed either count the results of a GROUP BY, e.g.

SELECT COUNT(*) FROM (SELECT * FROM a GROUP BY b)

or use COUNT(DISTINCT b):

SELECT COUNT(DISTINCT b) FROM a

After some puzzling around, I realised there was no built-in Laravel function for either of these. So the simplest solution was to use use DB::raw with the count method.

$count = $builder->count(DB::raw('DISTINCT b'));

Remember, don't use groupBy before calling count. You can apply groupBy later, if you need it for getting rows.

I had a similar problem, and found a way to work around it.

The problem is the way Laravel's query builder handles aggregates. It takes the first result returned and then returns the 'aggregate' value. This is usually fine, but when you combine count with groupBy you're returning a count per grouped item. So the first row's aggregate is just a count of the first group (so something low like 1 or 2 is likely).

So Laravel's count is out, but I combined the Laravel query builder with some raw SQL to get an accurate count of my grouped results.

For your example, I expect the following should work (and let you avoid the get):

$query = $ad->getcodes()->groupby('pid')->distinct();
$count = count(\DB::select($query->toSql(), $query->getBindings()));

If you want to make sure you're not wasting time selecting all the columns, you can avoid that when building your query:

 $query = $ad->select(DB::raw(1))->getcodes()->groupby('pid')->distinct();

You can use the following way to get the unique data as per your need as follows,

$data = $ad->getcodes()->get()->unique('email');

$count = $data->count();

Hope this will work.