atk4\data\tests\LimitOrderTest::testBasic PHP Method

    public function testBasic()
    {
        $a = ['invoice' => [['total_net' => 10], ['total_net' => 20], ['total_net' => 15]]];
        $this->setDB($a);
        $db = new Persistence_SQL($this->db->connection);
        $i = (new Model($db, 'invoice'))->addFields(['total_net', 'total_vat']);
        $i->addExpression('total_gross', '[total_net]+[total_vat]');
        $i->getElement('id')->system = false;
        $i->setOrder('total_net');
        $i->onlyFields(['total_net']);
        $this->assertEquals([['total_net' => 10], ['total_net' => 15], ['total_net' => 20]], $i->export());
    }