creating a custom database backend for django with non-standard sql

Backend
1

I’m working on a django project that needs to connect to a special database system. This database can be accessed through JDBC and ODBC connections, but it doesn’t use regular SQL commands that most databases support.

I tried using django-pyodbc to connect to it, but it crashes right away when trying to establish the connection. The problem is that django-pyodbc sends some built-in setup commands that my database doesn’t understand.

I know I could just use pyodbc directly in my code, but I’m wondering if there’s a way to build a custom database backend for django instead. I’ve found some examples for non-relational databases, but I need something for a relational database that just has different SQL syntax.

Has anyone created something like this before? Are there any guides or templates I should look at? Any advice on the best approach would be really helpful.

2

Creating a custom Django database backend is certainly feasible for your situation. You would start by subclassing django.db.backends.base.base.BaseDatabaseWrapper to override connection and query handling methods. It’s crucial to skip those default introspection commands causing crashes on your system. I recommend looking closely at existing Django backends, especially the sqlite3 one, as it provides a simpler foundation. Focus on modifying the _cursor method and the DatabaseIntrospection class to prevent Django from issuing those troublesome setup queries. Additionally, you can adjust DatabaseOperations to align with your specific SQL syntax. The challenging part will be mapping Django’s ORM functionalities to your database’s particular SQL dialect, but this approach will allow you to retain control over the connection process and leverage the ORM’s advantages.

3

Wow, that’s tricky! What database system are you working with? I’m curious about the SQL syntax differences - is it more NoSQL-like or just weird proprietary commands? Have you tried overriding the introspection parts first instead of building the entire backend?

4

hey, i built a custom db backend for a diff system once. subclassing is key! check out how postgresql does it, it’s super helpful. just be careful with the connection setup to avoid those unwanted commands. gl!