Multiple Data Entry in Django ORM

Question

I have been trying to create a way that my Django database will store data for 7 consecutive days because I want to use it to plot a weekly graph but the problem now is that Django doesn't have a datetime field that does that.

'''My Code'''
#Model to save seven consecutive days 
class SevenDayData(models.Model):
 
 '''Stores the date of the latest click and stores the value linked to that date in this case our clicks'''
 day1_date= models.DateField(default=None)
 day1_value= models.CharField(max_length=20)
 
 day2_date= models.DateField(default=None)
 day2_value= models.CharField(max_length=20)
 
 day3_date= models.DateField(default=None)
 day3_value= models.CharField(max_length=20)
 
 day4_date= models.DateField(default=None)
 day4_value= models.CharField(max_length=20)
 
 day5_date= models.DateField(default=None)
 day5_value= models.CharField(max_length=20)
 
 day6_date= models.DateField(default=None)
 day6_value= models.CharField(max_length=20)
 
 day7_date= models.DateField(default=None)
 day7_value= models.CharField(max_length=20)
 
 #updating the model each time the row is saved
 updated_at= models.DateTimeField(auto_now= True)
 
 #function that handles all the saving and switching of the 7 days
 def shift_days(self, new_value):
 
 #getting todays date
 today= date.today()
 
 #shifting every data out from day_7 each time a date is added i.e the 7th day is deleted from the db once the time is due
 self.day7_date, self.day7_value = self.day6_date, self.day6_value #Overwriting each date with the next one
 self.day6_date, self.day6_value = self.day5_date, self.day5_value
 self.day5_date, self.day5_value = self.day4_date, self.day4_value
 self.day4_date, self.day4_value = self.day3_date, self.day3_value
 self.day3_date, self.day3_value = self.day2_date, self.day2_value
 self.day2_date, self.day2_value = self.day1_date, self.day1_value
 
 #writing todays date into the day 1 which actually causes the shifting each time this db is accessed 
 self.day1_date, self.day1_value = today, new_value
 self.save()
'''Error'''
IntegrityError at /go/026099
null value in column "day2_date" of relation "url_shortner_sevendaydata" violates not-null constraint
DETAIL: Failing row contains (1, 2025年09月13日, 11, null, , null, , null, , null, , null, , null, , 2025年09月13日 15:16:30.262801+00).
Request Method: GET
Request URL: http://localhost:8000/go/026099
Django Version: 5.2.1
Exception Type: IntegrityError
Exception Value: 
null value in column "day2_date" of relation "url_shortner_sevendaydata" violates not-null constraint
DETAIL: Failing row contains (1, 2025年09月13日, 11, null, , null, , null, , null, , null, , null, , 2025年09月13日 15:16:30.262801+00).
Exception Location: C:\Users\VICT6OR\Desktop\Coding_backup\self_made.project\mini_url_app\env\Lib\site-packages\django\db\backends\utils.py, line 105, in _execute
Raised during: url_shortner.views.go_to_link
Python Executable: C:\Users\VICT6OR\Desktop\Coding_backup\self_made.project\mini_url_app\env\Scripts\python.exe
Python Version: 3.12.11
Python Path: 
['C:\\Users\\VICT6OR\\Desktop\\Coding_backup\\self_made.project\\mini_url_app',
 'C:\\Users\\VICT6OR\\miniforge3\\python312.zip',
 'C:\\Users\\VICT6OR\\miniforge3\\DLLs',
 'C:\\Users\\VICT6OR\\miniforge3\\Lib',
 'C:\\Users\\VICT6OR\\miniforge3',
 'C:\\Users\\VICT6OR\\Desktop\\Coding_backup\\self_made.project\\mini_url_app\\env',
 'C:\\Users\\VICT6OR\\Desktop\\Coding_backup\\self_made.project\\mini_url_app\\env\\Lib\\site-packages']
Server time: 2025年9月13日 15:16:30 +0000
'''The view giving me the error '''
def go_to_link(request, pk):
 '''Date clicked'''
 today = datetime.date.today()
 '''Clients IP address'''
 x_forwarded_for = request.META.get('HTTP_X_FORWARDED_FOR')
 if x_forwarded_for:
 ip = x_forwarded_for.split(',')[0] # first IP = client
 else:
 ip = request.META.get('REMOTE_ADDR')
 # Find the URLModel object
 url_details = URLModel.objects.get(uuid=pk)
 # Increment total clicks
 url_to_edit = URLModel.objects.filter(uuid=pk).first()
 url_to_edit.number_of_times_clicked += 1
 url_to_edit.save()
 # Save new click entry
 new_data = Click(url_relation=url_details, time_clicked=today, ip_address=ip)
 new_data.save()
 # --- Update SevenDayData ---
 record, created = SevenDayData.objects.get_or_create(
 id=1, # global; later you can tie this to url_details if you want per-link tracking
 defaults={
 "day1_date": today,
 "day1_value": str(url_to_edit.number_of_times_clicked),
 }
 )
 # Shift data forward and add today’s new click count
 record.shift_days(str(url_to_edit.number_of_times_clicked))
 return redirect(url_details.long_link)
# function to generate graph so we can analyze our number of clicks
def generate_graph(request, pk):
 # getting the url and the click data for each url
 url_details = URLModel.objects.filter(uuid=pk).first()
 click_details = Click.objects.filter(url_relation__uuid=pk).first()
 if not url_details or not click_details:
 return render(request, "graph.html", {"error": "No data available yet."})
 # getting date and the click count
 date_clicked = click_details.time_clicked
 times_clicked = url_details.number_of_times_clicked
 # Updating the seven day data model
 record, created = SevenDayData.objects.get_or_create(
 id=1,
 defaults={
 "day1_date": date_clicked,
 "day1_value": str(times_clicked),
 }
 )
 # Shift and add today's data if record already exists
 record.shift_days(str(times_clicked))
 # Build data arrays for plotting
 dates = [
 record.day1_date, record.day2_date, record.day3_date,
 record.day4_date, record.day5_date, record.day6_date, record.day7_date
 ]
 values = [
 int(record.day1_value or 0), int(record.day2_value or 0), int(record.day3_value or 0),
 int(record.day4_value or 0), int(record.day5_value or 0), int(record.day6_value or 0),
 int(record.day7_value or 0)
 ]
 # --- Plot the graph ---
 plt.figure(figsize=(8, 5))
 plt.plot(dates, values, marker="o", linestyle="-", color="blue")
 plt.title("Weekly Click Analytics")
 plt.xlabel("Date")
 plt.ylabel("Clicks")
 plt.xticks(rotation=30)
 plt.tight_layout()
 # Convert plot to base64 so we can embed it in HTML
 buf = io.BytesIO()
 plt.savefig(buf, format="png")
 buf.seek(0)
 graph = base64.b64encode(buf.read()).decode("utf-8")
 buf.close()
 # Render your template (graph.html)
 return render(request, "graph.html", {
 "url": url_details,
 "graph": f"data:image/png;base64,{graph}",
 })

Basically I want each time I click a link I want it to save the number of times the link was clicked and save the date at which the particular link was clicked but while saving I get a null error, and with that error I cant also generate a weekly graph analyzing the number of clicks so in summary I want to save daily amount of clicks for seven days but I have a null error

Answer 1

You here try to store None/NULL in the database for non-NULLable fields, you can make these NULLable with:

class SevenDayData(models.Model):
 day1_date = models.DateField(null=True, default=None)
 day1_value = models.CharField(null=True, max_length=20)
 day2_date = models.DateField(null=True, default=None)
 day2_value = models.CharField(null=True, max_length=20)
 day3_date = models.DateField(null=True, default=None)
 day3_value = models.CharField(null=True, max_length=20)
 day4_date = models.DateField(null=True, default=None)
 day4_value = models.CharField(null=True, max_length=20)
 day5_date = models.DateField(null=True, default=None)
 day5_value = models.CharField(null=True, max_length=20)
 day6_date = models.DateField(null=True, default=None)
 day6_value = models.CharField(null=True, max_length=20)
 day7_date = models.DateField(null=True, default=None)
 day7_value = models.CharField(null=True, max_length=20)
 # updating the model each time the row is saved
 updated_at = models.DateTimeField(auto_now=True)

But, a model should not be concerned how to enter data, it should focus on how to store data. You just store single entries, like:

class DayData(models.Model):
 day_date = models.DateField()
 day_value = models.CharField(max_length=20)

so you insert single data.

In case you want to retrieve then data from the last seven days, you can query with:

DayData.objects.filter(day_date__gte=datetime.now().date()-timedelta(days=7))

or if you want the last seven entries with:

DayData.objects.order_by('-day_date')[:7]