python - django 中的时间戳字段

Question

我有一个 MySQL 数据库，现在我正在生成所有日期时间字段作为 models.DateTimeField。有没有办法获取 timestamp 呢？我希望能够在创建和更新等时自动更新。

django 的文档没有这个？

Answer 1

实际上有一篇关于此的非常好且内容丰富的文章。这里: http://ianrolfe.livejournal.com/36017.html

页面上的解决方案略有过时，所以我做了以下操作:

from django.db import models
from datetime import datetime
from time import strftime

class UnixTimestampField(models.DateTimeField):
    """UnixTimestampField: creates a DateTimeField that is represented on the
    database as a TIMESTAMP field rather than the usual DATETIME field.
    """
    def __init__(self, null=False, blank=False, **kwargs):
        super(UnixTimestampField, self).__init__(**kwargs)
        # default for TIMESTAMP is NOT NULL unlike most fields, so we have to
        # cheat a little:
        self.blank, self.isnull = blank, null
        self.null = True # To prevent the framework from shoving in "not null".

    def db_type(self, connection):
        typ=['TIMESTAMP']
        # See above!
        if self.isnull:
            typ += ['NULL']
        if self.auto_created:
            typ += ['default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP']
        return ' '.join(typ)

    def to_python(self, value):
        if isinstance(value, int):
            return datetime.fromtimestamp(value)
        else:
            return models.DateTimeField.to_python(self, value)

    def get_db_prep_value(self, value, connection, prepared=False):
        if value==None:
            return None
        # Use '%Y%m%d%H%M%S' for MySQL < 4.1
        return strftime('%Y-%m-%d %H:%M:%S',value.timetuple())

要使用它，您所要做的就是: 时间戳 = UnixTimestampField(auto_created=True)

在 MySQL 中，该列应显示为: 'timestamp' timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,

唯一的缺点是它只适用于 MySQL 数据库。但是您可以轻松地为其他人修改它。