Django model history with foreign keys history tracking using django-simple-history

Question

I have three models with historical records:

class WifiUser(models.Model):
    ....
    wifiDevice = models.OneToOneField(WifiDevice, on_delete=models.CASCADE, default=None)
    wifiSim = models.OneToOneField(WifiSim, on_delete=models.CASCADE, default=None)
    history = HistoricalRecords()

class WifiDevice(models.Model):
    ....
    history = HistoricalRecords()

class WifiSim(models.Model):
    ....
    history = HistoricalRecords()

I want to keep track of history with corresponding foreign key history records. But when accessing the history of Wifiuser I get the latest values of WifiDevice and WifiSim. I want the historical record of WifiDevice and WifiSim to point to that record of their one. Whats the best method to follow for this ?

Use the `as_of()` method provided by SimpleHistory in your related models instances — ivissani, Jun 24 '20 at 11:29

score 0 · Answer 1 · answered Jun 19 '20 at 22:14

0

To keep track of the history and not have only the last object show,I suggest you add a model for the history,which contains the wifiUser wifiDevice and wifiSim,and maybe add a date for the access date and time, for auto adding the date I suggest you look at this answer (Django auto now and auto add now)

answered Jun 19 '20 at 22:14

B Z Ilyes

28
4

Hello, I think your approach may be the way to go. But how do you suggesting adding a model for the history with foreign keys? As the foreign key will point to the latest object. – Rashed Mazumder Jun 20 '20 at 04:50
You will be adding to the database,so each foreign key will be saved to their according object and having new foreign keys won't cause the data to be lost,just make sure you don't have a unique together attribute because that will cause integrity errors when having maybe a user that uses multiple devices. – B Z Ilyes Jun 20 '20 at 09:32

itjuba · Answer 2 · 2020-08-09T14:46:02.940

0

I saw your post in Upwork , you need to override the str method of both models WifiDevice & WifiSim as the following :


class WifiDevice(models.Model):
    ....
    history = HistoricalRecords()

    def __str__ (self):
    return self.history // the solution 




class WifiSim(models.Model):
    ....
    history = HistoricalRecords()
    def __str__ (self):
    return self.history // the solution

edited Aug 09 '20 at 14:46

answered Aug 08 '20 at 22:37

itjuba

518
4
23

score -2 · Answer 3 · answered Jun 24 '20 at 13:29

class BilingualCorpus(models.Model):
    file_url = models.FileField(upload_to='corpus_files/', validators=[FileExtensionValidator(allowed_extensions=['txt', 'csv', 'tmx', 'xlsx'])])
    file_name = models.CharField(max_length=255, default='none')
    name = models.CharField(max_length=50,default='none')
    s_lang = models.CharField(max_length=5,default='en')
    t_lang = models.CharField(max_length=5,default='th')
    note = models.TextField(blank=True)
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    created_at = models.DateTimeField(auto_now_add=True, blank=True)
    updated_at = models.DateTimeField(auto_now=True, blank=True)

class CorpusStatus(models.Model):
    status = models.CharField(max_length=50, default='Unchecked')

class  BilingualSentence(models.Model):
    corpus = models.ForeignKey(BilingualCorpus, on_delete=models.CASCADE)
    source = models.TextField(blank=True)
    target = models.TextField(blank=True)
    status = models.ForeignKey(CorpusStatus, blank=True, null=True, on_delete=models.SET_NULL)

Can you provide an explanation of how this solves the problem? Please be sure to use the edit button to add the explanation directly to your answer, instead of leaving it here in the comments. — Jeremy Caney, Jun 24 '20 at 15:59

Django model history with foreign keys history tracking using django-simple-history

3 Answers3