django-pg-utils
Utility methods for Django + PostgreSQL applications
What is this?
The utils module provides custom query expressions for Django, built on top of PostgreSQL functions. These can be used as a part of update, create, filter, order by, annotation, or aggregate. As with all query expressions, the computations leverage capabilities of the database, instead of loading data in the Django application.
Usage
pip install django-pg-utils
from pg_utils import DateTZ, divide
queryset.annotate(created_date=DateTZ(F('created_at'), '+05:30')
queryset.annotate(speed=divide(F('distance'), F('time')))
| Query expression | Use case |
|---|---|
| Date | Cast datetime field into date |
| DateTZ | Cast datetime field into date and change timezone if required |
| Seconds | Cast difference of datetime fields (durations) into seconds |
| DistinctSum | Compute SUM of values with the DISTINCT flag |
| Float | Cast integer field to float |
| NullIf | Return NULL if value is 0 |
| divide | Divide two integer or float columns and return a float |
| multiply | Multiply two integer or float columns and return a float |
| add | Add two integer or float columns and return a float |
| subtract | Subtract two integer or float columns and return a float |
| LeftPad | Because no package should ever be uploaded without left pad |
Tests
To run tests with coverage, you will need the coverage package.
pip install coverage
coverage run --source=./pg_utils tests/runtests.py
coverage report
Contribute
We would love to have your contributions! To contribute to the repo, please open an issue or create a pull request.
