Laravel 中的 timestampTz 字段

Question

Laravel 5.4 在迁移中支持 Postgres TIMESTAMP WITH TIME ZONE 字段类型：

$table->timestampTz('scheduled_for');

Laravel 可以设置为将日期字段（DATE、DATETIME、TIMESTAMP）转换为 Carbon 对象（默认情况下，created_at 和 updated_atTIMESTAMP 字段会这样做），但是将scheduled_for 放入$dates 字段会导致时区感知版本出错：

InvalidArgumentException with message 'Trailing data'

查看数据库和修补程序，该字段的值似乎类似于2017-06-19 19:19:19-04。是否有从这些字段类型之一中获取 Carbon 对象的本机方法？还是我使用访问器卡住了？

Answer 1

复活这个问题，希望有一个有用的答案被接受。

Laravel 采用 Y-m-d H:i:s 数据库时间戳格式。如果您使用的是 Postgres timestampz 列，那显然是不同的。您需要告诉 Eloquent 如何让 Carbon 解析该格式。

只需像这样在模型上定义 $dateFormat 属性：

Class MyModel extends Eloquent {

    protected $dateFormat = 'Y-m-d H:i:sO';

}

信用到期：我在GitHub issue 中找到了这个解决方案

Answer 2

把它放在你的模型中

protected $casts = [
    'scheduled_for' => 'datetime'   // date | datetime | timestamp
];

使用$dates 更可能过时，因为$casts 做同样的事情（可能除了$dateFormat 属性，它只能用于$dates 字段iirc，但我看到一些抱怨）

编辑

我曾经在 Laravel 5.4 上测试过 Carbon，并为它创建了一个 trait

这还不是生产级代码，因此请将其包含在您的模型中，风险自负

<?php namespace App\Traits;

use Carbon\Carbon;

trait castTrait
{
    protected function castAttribute($key, $value)
    {
        $database_format        = 'Y-m-d H:i:se';   // Store this somewhere in config files
        $output_format_date     = 'd/m/Y';          // Store this somewhere in config files
        $output_format_datetime = 'd/m/Y H:i:s';    // Store this somewhere in config files

        if (is_null($value)) {
            return $value;
        }

        switch ($this->getCastType($key)) {
            case 'int':
            case 'integer':
                return (int) $value;
            case 'real':
            case 'float':
            case 'double':
                return (float) $value;
            case 'string':
                return (string) $value;
            case 'bool':
            case 'boolean':
                return (bool) $value;
            case 'object':
                return $this->fromJson($value, true);
            case 'array':
            case 'json':
                return $this->fromJson($value);
            case 'collection':
                return new BaseCollection($this->fromJson($value));
            case 'date':
                Carbon::setToStringFormat($output_format_date);
                $date = (string)$this->asDate($value);
                Carbon::resetToStringFormat();  // Just for sure
                return $date;
            case 'datetime':
                Carbon::setToStringFormat($output_format_datetime);
                $datetime = (string)$this->asDateTime($value);
                Carbon::resetToStringFormat();
                return $datetime;
            case 'timestamp':
                return $this->asTimestamp($value);
            default:
                return $value;
        }
    }

    /**
     * Return a timestamp as DateTime object with time set to 00:00:00.
     *
     * @param  mixed  $value
     * @return \Carbon\Carbon
     */
    protected function asDate($value)
    {
        return $this->asDateTime($value)->startOfDay();
    }

    /**
     * Return a timestamp as DateTime object.
     *
     * @param  mixed  $value
     * @return \Carbon\Carbon
     */
    protected function asDateTime($value)
    {
        $carbon = null;
        $database_format = [ // This variable should also be in config file
            'datetime'  => 'Y-m-d H:i:se',      // e -timezone
            'date'      => 'Y-m-d'
        ];

        if(empty($value)) {
            return null;
        }

        // If this value is already a Carbon instance, we shall just return it as is.
        // This prevents us having to re-instantiate a Carbon instance when we know
        // it already is one, which wouldn't be fulfilled by the DateTime check.
        if ($value instanceof Carbon) {
            $carbon = $value;
        }

         // If the value is already a DateTime instance, we will just skip the rest of
         // these checks since they will be a waste of time, and hinder performance
         // when checking the field. We will just return the DateTime right away.
        if ($value instanceof DateTimeInterface) {
            $carbon = new Carbon(
                $value->format($database_format['datetime'], $value->getTimezone())
            );
        }

        // If this value is an integer, we will assume it is a UNIX timestamp's value
        // and format a Carbon object from this timestamp. This allows flexibility
        // when defining your date fields as they might be UNIX timestamps here.
        if (is_numeric($value)) {
            $carbon = Carbon::createFromTimestamp($value);
        }

        // If the value is in simply year, month, day format, we will instantiate the
        // Carbon instances from that format. Again, this provides for simple date
        // fields on the database, while still supporting Carbonized conversion.
        if ($this->isStandardDateFormat($value)) {
            $carbon = Carbon::createFromFormat($database_format['date'], $value)->startOfDay();
        }

        // Finally, we will just assume this date is in the format used by default on
        // the database connection and use that format to create the Carbon object
        // that is returned back out to the developers after we convert it here.
        $carbon = Carbon::createFromFormat(
            $database_format['datetime'], $value
        );

        return $carbon;
    }
}