PostgreSQL: Unexpected NULL Values in JSONB Aggregation After Grouping
I've spent hours debugging this and I'm relatively new to this, so bear with me. I'm working with an scenario when trying to aggregate JSONB data in PostgreSQL 13. The goal is to group records by a specific field and then aggregate some JSONB columns. However, I'm getting unexpected NULL values in the output, which is not what I expect. Here's a simplified version of my query: ```sql SELECT department_id, JSONB_AGG(employee_info) AS employees FROM ( SELECT department_id, JSONB_BUILD_OBJECT('id', employee_id, 'name', employee_name) AS employee_info FROM employees WHERE hire_date > '2022-01-01' ) AS subquery GROUP BY department_id; ``` The `employee_info` JSONB object is generated correctly in the subquery, but when I perform the aggregation with `JSONB_AGG`, some departments end up with NULL values instead of an empty array. I tried adding `COALESCE` around the `JSONB_AGG` call, but it doesn't seem to make a difference. The data structure is correct, and I'm certain that there are employees hired after the given date; I'm just not seeing them in the output. I've verified that the `department_id` is not NULL for any of the records being selected. To troubleshoot, I ran the subquery independently, and it returns the expected results. Is there something about how JSONB aggregation works with GROUP BY that I'm missing? Any insights would be greatly appreciated! For context: I'm using Sql on Ubuntu. What am I doing wrong? I'm working in a macOS environment. Cheers for any assistance!