Data not getting saved in table using Model

Using Django Using the ORM
1

Hi All,
Just started playing around with Django. Created a basic app. And am trying to create a model and save data to corresponding table in sqlite. Wrote a test to check the model and save operation. But somehow the data is not getting saved in the table. The table has got created when i ran migrate command. The model is pretty simple:

from django.db import models

class JD(models.Model):
    job_id = models.TextField()
    role = models.CharField(max_length=100)
    experience = models.IntegerField()

    def save(self, *args, **kwargs):
        super().save(*args, **kwargs)

Test is as follows:

from django.test import TestCase
from .jd import JD
class JDModelTest(TestCase):
    def test_job_id_label(self):
        JD.objects.create(job_id='1', role='Software Engineer', experience=2)

        jd = JD.objects.get(id=1)
        field_label = jd._meta.get_field('job_id').verbose_name
        self.assertEquals(field_label, 'job id')

When I run the tests, they do pass and i dont see any error/exception:

:test_job_id_label
./myapp/allmodels/test_jd.py::JDModelTest::test_job_id_label Passed
Total number of tests expected to run: 1
Total number of tests run: 1
Total number of tests passed: 1
Total number of tests failed: 0
Total number of tests failed with errors: 0
Total number of tests skipped: 0
Finished running tests!

The table is created but it doesnt have any record.

I debugged and the problem seems to be due to the code “if isinstance(params, Mapping)” in the ./lib/python3.10/site-packages/django/db/backends/sqlite3/base.py

    def execute(self, query, params=None):
        if params is None:
            return super().execute(query)
        # Extract names if params is a mapping, i.e. "pyformat" style is used.
        param_names = list(params) if isinstance(params, Mapping) else None
        query = self.convert_query(query, param_names=param_names)
        return super().execute(query, params)

The “params” parameter is a tuple rather than a dictionary or a list. Its created in the function " def as_sql(self)" of /lib/python3.10/site-packages/django/db/models/sql/compiler.py (the “tuple” in the list)

            if r_sql:
                result.append(r_sql)
                params += [self.returning_params]
            return [(" ".join(result), tuple(chain.from_iterable(params)))]

Following is my project structure:

TRYDJANGO (WORKSPACE)
├── TryDjango
│   ├── .vscode
│   │   └── settings.json
│   └── tryapp
│       ├── myapp
│       │   ├── __pycache__
│       │   │   └── allmodels
│       │   └── __pycache__
│       │       └── __init__.py
│       │       └── jd.py
│       │           → test_jd.py
│       │   └── migrations
│       │       ├── __init__.py
│       │       ├── admin.py
│       │       ├── apps.py
│       │       ├── models.py
│       │       └── tests.py
│       │       └── views.py
│       └── tryapp
│           ├── __pycache__
│           └── __init__.py
│           └── asgi.py
│           └── settings.py
│               → urls.py
│           └── wsgi.py
└── db.sqlite3
    → manage.py

I am using conad env with python 3.10 and Django 4.2.6, and have also tried with python 3.11.5 and Django 4.2.7.
It is likely that I am missing something very basic, but havent been able to put my finger on. Any help will be greatly appreciated.

TIA
~Anand.

2

Side note: When posting code here, enclose the code between lines of three backtick - ` characters. That means you will have a line of ```, then your code, then another line of ```. (I’ve taken the liberty of editing your original post, please remember to do this in the future.)

What are you looking at to determine that no row has been created? Do you have your tests set up to use a test database? (Also see Database transactions | Django documentation | Django)

3

Noted on the posting guideline and thanks for correcting & informing.
After the test is executed, I am checking the table in db using a client (dbeaver). there are no values in the table.
Would like to elaborate a bit more on the following:

    def execute(self, query, params=None):
        if params is None:
            return super().execute(query)
        # Extract names if params is a mapping, i.e. "pyformat" style is used.
        param_names = list(params) if isinstance(params, Mapping) else None
        query = self.convert_query(query, param_names=param_names)
        return super().execute(query, params)

As the ‘’’ isinstance(params, Mapping) ‘’’ condition fails, the “param_names” does not have any values for the data and insert query is built without any values. from there on the behavior would be expected.
Am trying with PostgreSQL. Will update.

4

Right. See the docs I referenced above regarding transactions in test cases.