👀 Views: 61 💬 Answers: 1 📅 Created: 2025-06-12

SQLite JOIN COALESCE SQL

I'm migrating some code and I tried several approaches but none seem to work... I'm working with SQLite and working with an scenario where my LEFT JOIN results seem incorrect when I use the `COALESCE` function to handle NULL values. I have two tables: `users` and `orders`. The `users` table contains user information, and the `orders` table has order details. I want to retrieve all users along with their associated order IDs, but in cases where a user has no orders, I want the order ID to default to 0. Here’s the SQL query I’m using: ```sql SELECT u.id AS user_id, COALESCE(o.id, 0) AS order_id FROM users u LEFT JOIN orders o ON u.id = o.user_id; ``` However, I'm getting unexpected results. When a user has multiple orders, I see multiple rows for that user, which is expected, but when a user has no orders, I still get NULL instead of 0 for the `order_id`. Here’s a sample output: ``` user_id | order_id -------- | --------- 1 | 3 1 | 4 2 | NULL 3 | 0 ``` It seems like the `COALESCE` function is not working as intended for users with no orders. I’ve verified that the `users` table has users without any orders, and I expect the result for user 2 to show `0` instead of `NULL`. I’ve tried modifying the `COALESCE` function to use a different default value, but it hasn’t corrected the output. Could there be an scenario with how SQLite handles the LEFT JOIN with NULL values, or am I missing something in my query logic? I've also checked the SQLite version I’m using, which is 3.34.1, ensuring it supports the COALESCE function. Any insights on what might be going wrong or how to fix this scenario would be greatly appreciated! My team is using Sql for this web app. Any suggestions would be helpful. My development environment is Windows 10. Any ideas how to fix this?