source/Application/Model/Order.php
public function getInvoiceNum()
    {
        $sQ = 'select max(oxorder.oxinvoicenr) from oxorder where oxorder.oxshopid = "' . \OxidEsales\Eshop\Core\Registry::getConfig()->getShopId() . '" ';

        return (( int ) \OxidEsales\Eshop\Core\DatabaseProvider::getDb()->getOne($sQ, false) + 1);
    }
public function getInvoiceNum()
    {
        $sQ = 'select max(oxorder.oxinvoicenr) from oxorder where oxorder.oxshopid = "' . \OxidEsales\Eshop\Core\Registry::getConfig()->getShopId() . '" ';

        return (( int ) \OxidEsales\Eshop\Core\DatabaseProvider::getDb()->getOne($sQ, false) + 1);
    }
public function getInvoiceNum ( ) { $ sQ = 'select max(oxorder.oxinvoicenr) from oxorder where oxorder.oxshopid = "' . \ OxidEsales \ Eshop \ Core \ Registry :: getConfig ( ) -> getShopId ( ) . '" ' ; return ( ( int ) \ OxidEsales \ Eshop \ Core \ DatabaseProvider :: getDb ( ) -> getOne ( $ sQ , false ) + 1 ) ; }
Returns order invoice number.

@return integer
Returns order invoice number .