用於導入表格數據的Django ForeignKey

Question

我有兩張表格，School和Scores，它們有一個共同的'psid'列。我將每個表格中的數據導入到我的應用程序中。我想通過一個ForeignKey將兩個表連接在一起（一個學校可以有多個分數）。

目前我models.py看起來是這樣的：

class School(models.Model): 
    psid = models.CharField(primary_key=True, max_length=5) 
    city = models.CharField(max_length=100) 

class Score(models.Model): 
    psid = models.ForeignKey(School, max_length=5, db_column='psid') 
    scores = models.IntegerField(max_length=2) 

我需要在分數的附加字段，這樣我既可以導入從原始表的PSID列，並已鏈接得分一個ForeignKey字段，通過'psid'專欄一起學校？

任何幫助表示讚賞。

Answer 1

django模型處理大多數情況下在幕後鏈接表格。 ForeignKey字段類型足以實現此目的，那麼您只需使用ORM在查詢中加入表。這是我怎麼會設置您的表基於我最好的解讀一下你正在尋找：

from django.db import models 


class School(models.Model): 
    psid = models.CharField(primary_key=True, max_length=5) 
    city = models.CharField(max_length=100) 

    def __unicode__(self): 
     return u"{0} ({1})".format(self.psid, self.city) 


class Score(models.Model): 
    school = models.ForeignKey(School, null=False, db_column="psid") 
    score = models.IntegerField() 

    def __unicode__(sefl): 
     return u"Score({0}, {1})".format(self.school.psid, self.score) 

然後以測試你的模型了：

$ ./manage.py syncdb 
$ ./manage.py shell 
>>> from schools.models import School, Score 
>>> school1 = School(psid="S1", city="Springfield") 
>>> school1 
S1 (Springfield) 
>>> school1.save() 
>>> School.objects.get(psid="S1") 
S1 (Springfield) 
>>> school2 = School(psid="S2", city="Springfield") 
>>> school2.save() 
>>> score1 = Score(school=school1, score=3) 
>>> score1 
Score(S1, 3) 
>>> score1.school.psid 
S1 
>>> score2 = Score(school=school1, score=2) 
>>> score3 = Score(school=school2, score=5) 
>>> score1.save() 
>>> score2.save() 
>>> score3.save() 
>>> school1.score_set.all() 
[Score(S1, 3), Score(S1, 2)] 
>>> school2.score_set.all() 
[Score(S2, 5)] 
>>> Score.objects.all() 
[Score(S1, 3), Score(S1, 2), Score(S2, 5)] 
>>> Score.objects.filter(school__psid="S1") 
[Score(S1, 3), Score(S1, 2)] 

我希望可以幫助你。