CODEWITHSUNDEEP
pythondjango
John Smith
John Smith

Reputation: 2738

A good approach to know existence of a record in a table

I have next model:

class People(models.Model):
    name = models.CharField(max_length=100)
    lastname = models.CharField(max_length=100)

In views.py

-When I try this one:

 if People.objects.get(id=my_id):
        o=People.objects.get(id=my_id)
        oh=o.name
    else:
        send_notification_to_add_that_id(my_id)

I get this:

People query matching does not exist.

What I want is that Query the my_id in my People table, if there is a match with that record get the id, else trigger the send_notification_to_add_that_id method. When first "if conditions" does not have such a record, i am getting above error. How to by pass this issue? What is the good approach to know existence of a record in a table ?

Upvotes: 0

Views: 57

Answers (1)

Timmy O'Mahony
Timmy O'Mahony

Reputation: 53998

It's throwing an exception:

If there are no results that match the query, get() will raise a DoesNotExist exception.

so you need to handle it:

try:
    People.objects.get(id=my_id)
except People.DoesNotExist:
    send_notification_to_add_that_id(my_id)

alternativly you could do

people = People.objects.filter(id=my_id)
if people.exists():
    person = people[0]

as filter doesn't raise an exception if there are no results - it simply returns an empty QuerySet but this runs the risk of returning more then one object, so it doesn't make as much sense as the first example.

As an aside, it makes more sense to call your model Person instead of People as that is what is being represented by your model or in the case of the DB, each row in your table.

Upvotes: 4

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