atk4\data\Persistence_SQL::_typecastLoadField PHP Method

    public function _typecastLoadField(Field $f, $value)
    {
        // work only on copied value not real one !!!
        $v = is_object($value) ? clone $value : $value;
        switch ($f->type) {
            case 'integer':
                $v = (int) $v;
                break;
            case 'float':
                $v = (double) $v;
                break;
            case 'money':
                $v = round($v, 4);
                break;
            case 'boolean':
                if (isset($f->enum) && is_array($f->enum)) {
                    if (isset($f->enum[0]) && $v == $f->enum[0]) {
                        $v = false;
                    } elseif (isset($f->enum[1]) && $v == $f->enum[1]) {
                        $v = true;
                    } else {
                        $v = null;
                    }
                } else {
                    $v = (bool) $v;
                }
                break;
            case 'date':
            case 'datetime':
            case 'time':
                $dt_class = isset($f->dateTimeClass) ? $f->dateTimeClass : 'DateTime';
                $tz_class = isset($f->dateTimeZoneClass) ? $f->dateTimeZoneClass : 'DateTimeZone';
                if (is_numeric($v)) {
                    $v = new $dt_class('@' . $v);
                } elseif (is_string($v)) {
                    // ! symbol in date format is essential here to remove time part of DateTime - don't remove, this is not a bug
                    $format = ['date' => '+!Y-m-d', 'datetime' => 'Y-m-d H:i:s', 'time' => 'H:i:s'];
                    $format = $f->persist_format ?: $format[$f->type];
                    // datetime only - set from persisting timezone
                    if ($f->type == 'datetime' && isset($f->persist_timezone)) {
                        $v = $dt_class::createFromFormat($format, $v, new $tz_class($f->persist_timezone));
                        if ($v === false) {
                            throw new Exception(['Incorrectly formatted datetime', 'format' => $format, 'value' => $value, 'field' => $f]);
                        }
                        $v->setTimeZone(new $tz_class(date_default_timezone_get()));
                    } else {
                        $v = $dt_class::createFromFormat($format, $v);
                        if ($v === false) {
                            throw new Exception(['Incorrectly formatted date/time', 'format' => $format, 'value' => $value, 'field' => $f]);
                        }
                    }
                    // need to cast here because DateTime::createFromFormat returns DateTime object not $dt_class
                    // this is what Carbon::instance(DateTime $dt) method does for example
                    if ($dt_class != 'DateTime') {
                        $v = new $dt_class($v->format('Y-m-d H:i:s.u'), $v->getTimeZone());
                    }
                }
                break;
            case 'array':
                // don't decode if we already use some kind of serialization
                $v = $f->serialize ? $v : json_decode($v, true);
                break;
            case 'object':
                // don't decode if we already use some kind of serialization
                $v = $f->serialize ? $v : json_decode($v, false);
                break;
        }
        return $v;
    }