我决定采取不同的方法,并选择不使用注释。我向作业模型中添加了一个管理器,该管理器仅返回活动(30天或更少的旧作业),并在JobCategory模型上创建一个属性,以查询实例的作业计数。我的模板标签只是返回所有类别。这是相关的代码。
class JobCategory(models.Model):
title = models.CharField(_('title'), max_length=50, help_text=_("Max 50 chars. Required."))
slug = models.SlugField(_('slug'), help_text=_("Only letters, numbers, or hyphens. Required."))
class Meta:
verbose_name = _('job category')
verbose_name_plural = _('job categories')
def __unicode__(self):
return self.title
def get_absolute_url(self):
return reverse('djobs_category_jobs', args=[self.slug])
@property
def active_job_count(self):
return len(Job.active.filter(category=self))
class ActiveJobManager(models.Manager):
def get_query_set(self):
return super(ActiveJobManager, self).get_query_set().filter(created_date__gte=datetime.datetime.now() - datetime.timedelta(days=30))
class Job(models.Model):
title = models.CharField(_('title'), max_length=50, help_text=_("Max 50 chars. Required."))
description = models.TextField(_('description'), help_text=_("Required."))
category = models.ForeignKey(JobCategory, related_name='jobs')
employment_type = models.CharField(_('employment type'), max_length=5, choices=EMPLOYMENT_TYPE_CHOICES, help_text=_("Required."))
employment_level = models.CharField(_('employment level'), max_length=5, choices=EMPLOYMENT_LEVEL_CHOICES, help_text=_("Required."))
employer = models.ForeignKey(Employer)
location = models.ForeignKey(Location)
contact = models.ForeignKey(Contact)
allow_applications = models.BooleanField(_('allow applications'))
created_date = models.DateTimeField(auto_now_add=True)
objects = models.Manager()
active = ActiveJobManager()
class Meta:
verbose_name = _('job')
verbose_name_plural = _('jobs')
def __unicode__(self):
return '%s at %s' % (self.title, self.employer.name)
和标签...
def job_categories():
categories = JobCategory.objects.all()
return {'categories': categories}
这将返回只有那些在过去30天内创建工作的类别。我也试图避免返回多个查询集,因为这违反了使用注释的目的。这个函数实际上是作为模板标签存在的,我希望在模板层中包含每个类别的计数(即使计数为0)。谢谢你。 – gsiegman 2009-08-18 13:31:58
是的,我认为你只需要执行两个查询。 – monkut 2009-08-19 00:47:30