PostgreSQL: Unexpected NULL values in JSONB when using LEFT JOIN
I'm sure I'm missing something obvious here, but I am working with a question with my PostgreSQL query where performing a `LEFT JOIN` on tables containing JSONB fields results in unexpected NULL values... I have two tables: `users` and `user_details`. The `user_details` table has a JSONB column containing various attributes. When I run the following query: ```sql SELECT u.id, u.name, ud.details FROM users u LEFT JOIN user_details ud ON u.id = ud.user_id; ``` I expect to get all users from the `users` table along with their details from the `user_details` table. However, I am getting NULL for the `ud.details` column for some users, even though I can confirm that there are corresponding entries in `user_details`. After checking the data, it appears that the scenario arises only when the `user_details` JSONB column is empty. For instance, if a user has an associated row in `user_details` but the `details` field is an empty JSON object (`{}`), the LEFT JOIN still returns NULL for that user in the result set. I have verified that the join condition is correct and have also tried using `COALESCE` to handle this, but it doesn't seem to resolve the scenario. Here’s the relevant part of my data: ```sql CREATE TABLE users ( id SERIAL PRIMARY KEY, name TEXT NOT NULL ); CREATE TABLE user_details ( user_id INT REFERENCES users(id), details JSONB ); INSERT INTO users (name) VALUES ('Alice'), ('Bob'); INSERT INTO user_details (user_id, details) VALUES (1, '{}'), (2, '{"age": 30, "city": "New York"}'); ``` When running the join, I expect to see: ``` 1 | Alice | {} 2 | Bob | {"age": 30, "city": "New York"} ``` But instead, I get: ``` 1 | Alice | NULL 2 | Bob | {"age": 30, "city": "New York"} ``` Is there a way to modify my query or handle this situation so that I still get the empty JSON object in the result instead of NULL? Thanks in advance! My development environment is macOS. Is there a better approach? I've been using Sql for about a year now. Cheers for any assistance! Any ideas what could be causing this?