atk4\data\tests\ExpressionSQLTest::testReloading PHP Method

    public function testReloading()
    {
        $a = ['math' => [['a' => 2, 'b' => 2]]];
        $this->setDB($a);
        $db = new Persistence_SQL($this->db->connection);
        $m = new Model($db, 'math');
        $m->addFields(['a', 'b']);
        $m->addExpression('sum', '[a] + [b]');
        $m->load(1);
        $this->assertEquals(4, $m['sum']);
        $m->save(['a' => 3]);
        $this->assertEquals(5, $m['sum']);
        $this->assertEquals(9, $m->unload()->save(['a' => 4, 'b' => 5])->get('sum'));
        $this->setDB($a);
        $m = new Model($db, ['math', 'reload_after_save' => false]);
        $m->addFields(['a', 'b']);
        $m->addExpression('sum', '[a] + [b]');
        $m->load(1);
        $this->assertEquals(4, $m['sum']);
        $m->save(['a' => 3]);
        $this->assertEquals(4, $m['sum']);
        $this->assertEquals(null, $m->unload()->save(['a' => 4, 'b' => 5])->get('sum'));
    }