Django QuerySet Filters optimization guide with Composite Fields in PostgreSQL
I'm working on a project and hit a roadblock. After trying multiple solutions online, I still can't figure this out. I'm converting an old project and I'm working with an scenario where the `filter` method on my Django QuerySet does not return the expected results when using composite fields in a PostgreSQL database... I'm trying to filter users based on a concatenated field of first name and last name that I've created as a composite field. Here's how I've set it up: In my `models.py`, I have: ```python from django.db import models class User(models.Model): first_name = models.CharField(max_length=30) last_name = models.CharField(max_length=30) class Meta: indexes = [ models.Index(fields=['first_name', 'last_name'], name='full_name_idx') ] ``` And I created a composite field in my database like this: ```sql CREATE INDEX full_name_idx ON myapp_user USING btree (first_name || ' ' || last_name); ``` Then in my view, I attempt to filter users like this: ```python from .models import User def get_full_name_users(request): search_term = 'John Doe' users = User.objects.filter(first_name + ' ' + last_name = search_term) return users ``` However, I'm getting the behavior `SyntaxError: want to use assignment operator in this context`. I've also tried using `F` expressions, but it still doesn't return results as expected: ```python from django.db.models import F users = User.objects.filter(F('first_name') + ' ' + F('last_name') = search_term) ``` The query returns an empty list even when I know there are matching records in the database. Am I missing something with how to properly construct the filter for composite fields in Django? Any help or insights would be greatly appreciated! I'm using Django 3.2 with PostgreSQL 13. I'm working on a REST API that needs to handle this. I'd love to hear your thoughts on this. I'm using Python 3.10 in this project. Thanks in advance!