How to get Average Cpv from campagn table with GAQL

[임호재]

Just get error,  

Uncaught Error: Call to a member function getValue()

Why getAverageCpv() is not working. 

My campaign has averge cpv, not null.

public static function runExample(GoogleAdsClient $googleAdsClient, $customerId)

    {

        $googleAdsServiceClient = $googleAdsClient->getGoogleAdsServiceClient();

        // Creates a query that retrieves all keyword statistics.

        $query =

            "SELECT campaign.id, campaign.name, campaign.status, segments.device, metrics.impressions,

       metrics.clicks, metrics.ctr, metrics.average_cpv, metrics.average_cpc, metrics.cost_micros

FROM campaign

WHERE segments.date DURING YESTERDAY";

        // Issues a search request by specifying page size.

        $response =

            $googleAdsServiceClient->search($customerId, $query, ['pageSize' => self::PAGE_SIZE]);

        // Iterates over all rows in all pages and prints the requested field values for

        // the keyword in each row.

        foreach ($response->iterateAllElements() as $googleAdsRow) {

            /** @var GoogleAdsRow $googleAdsRow */

            $campaign = $googleAdsRow->getCampaign();

$metrics = $googleAdsRow->getMetrics();

            

printf(

                "campaign name '%s' "

                . "ID %d "

. "cpv %s "

. "cost %s "

. "%s",

                $campaign->getName()->getValue(),

                $campaign->getId()->getValue(),

$metrics->getAverageCpv()->getValue(),

$metrics->getCostMicros()->getValue(),

                PHP_EOL

            );

        }

    }

[임호재]

Dear Google API team,

I get Just this Error, our campaign has average cpv not null.

Uncaught Error: Call to a member function getValue()

source :