value method on Query Builder returns _id instead of passed value

[goodevilgenius]

Take the following code:

app('db')->connection('mongodb')->table($collectionName)
    ->where($key, $value)->value($propertyName);

If using mysql, it runs a query like:

SELECT $propertyName FROM $collectionName WHERE $key = $value LIMIT 1

And it returns the value of $propertyName.

See https://github.com/illuminate/database/blob/8b600637ff7f472bc41705b5a7dabe9501eebe56/Query/Builder.php#L2027

However, due to the fact that mongo always returns the _id, whenever you use a projection, this method always returns _id, instead of $propertyName

This method should be overriden with something like:

public function value($column)
{
    $result = (array) $this->first([$column]);

    return $result[$column] ?? null;
}