python - Django - 如何链接表格

Question

你好，stackoverflow 团队，

我有以下两个 django 表:

class StraightredFixture(models.Model):
    fixtureid = models.IntegerField(primary_key=True)
    soccerseason = models.IntegerField(db_column='soccerSeason')  # Field name made lowercase.
    hometeamid = models.IntegerField()
    awayteamid = models.IntegerField()
    fixturedate = models.DateTimeField()
    fixturestatus = models.CharField(max_length=24)
    fixturematchday = models.IntegerField()
    hometeamscore = models.IntegerField()
    awayteamscore = models.IntegerField()

    class Meta:
        managed = False
        db_table = 'straightred_fixture'

class StraightredTeam(models.Model):
    teamid = models.IntegerField(primary_key=True)
    teamname = models.CharField(max_length=36)
    teamcode = models.CharField(max_length=5)
    teamshortname = models.CharField(max_length=24)

    class Meta:
        managed = False
        db_table = 'straightred_team'

在 views.py 中，我知道我可以放入以下内容并且它完美地工作:

def test(request):
    fixture = StraightredFixture.objects.get(fixtureid=136697)
    return render(request,'straightred/test.html',{'name':fixture.hometeamid})

正如我上面提到的，这一切都很好，但我希望返回可以在 StraightredTeam 模型中找到的 hometeamid 的团队名称。

环顾四周后，我被推向了“select_related”的方向，但我不清楚如何在我现有的表中实现它，也不清楚它是否是此类查询的最有效方式。感觉不错。

请注意此代码是使用“python manage.py inspectdb”创建的。

在此阶段提出任何建议，我们将不胜感激。非常感谢，艾伦。

Answer 1

参见 model relationships .

Django 提供了特殊的模型字段来管理表关系。适合您需要的是 ForeignKey .

而不是声明:

hometeamid = models.IntegerField()
awayteamid = models.IntegerField()

我猜这是 python manage.py inspectdb 的结果，你会声明:

home_team = models.ForeignKey('<app_name>. StraightredTeam', db_column='hometeamid', related_name='home_fixtures')
away_team = models.ForeignKey('<app_name>. StraightredTeam', db_column='awayteamid', related_name='away_fixtures')

通过执行此操作，您将告诉 Django ORM 处理引擎盖下的关系，这将允许您执行以下操作:

fixture = StraightredFixture.objects.get(fixtureid=some_fixture_id)
fixture.home_team  # Returns the associated StraightredTeam instance.

team = StraightredTeam.objects.get(team_id=some_team_id)
team.home_fixtures.all()  # Return all at home fixtures for that team.