How to average multiple columns using Eloquent?

eloquent, laravel

Solution

To avoid multiple queries you can use a raw database expression within Eloquent as shown below:

$averages = $this->reviews()
    ->select(DB::raw('avg(communication) c, avg(friendliness) f'))
    ->first();

echo $averages->c;
echo $averages->f;

Since the aggregate function name `avg` is recognized by all supported database by Laravel, this will not be a big deal.

Problem

I'm looking to get the average value across multiple columns on a related model, something like this: ``` $this->reviews()->avg('communication', 'friendliness') ``` Where communication and friendliness are an array of column names. However it appears the aggregate functions only support single column names, so I'm doing this: ``` $attributes = array('communication', 'friendliness'); $score = array(); foreach ($attributes as $attribute) { $score[] = $this->reviews()->avg($attribute); } return round(array_sum($score) / sizeof($attributes), 1); ``` Which results in multiple queries. Any suggestions for a best practice here? Thanks

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