MySQL 8.0: Inconsistent results with CASE statement inside GROUP BY clause
I've encountered a strange issue with I'm stuck on something that should probably be simple. I'm stuck on something that should probably be simple. After trying multiple solutions online, I still can't figure this out... I'm experiencing inconsistent results when using a CASE statement within a GROUP BY clause in MySQL 8.0. I have a table named `sales` with the following structure: ```sql CREATE TABLE sales ( id INT PRIMARY KEY, product VARCHAR(100), amount DECIMAL(10, 2), sale_date DATE ); ``` Here's the query Iām trying to execute: ```sql SELECT CASE WHEN amount > 100 THEN 'High' ELSE 'Low' END AS sale_category, SUM(amount) AS total_sales FROM sales GROUP BY sale_category; ``` What I expect is to see a breakdown of total sales grouped by the defined categories ('High' and 'Low'). However, I'm getting unexpected results where some categories seem to be missing from the result set. For instance, if there are no sales in the 'High' category, it doesn't appear in the results at all, which is fine, but I also noticed that sometimes the 'Low' category does not appear either, even when I have sales below the threshold. To troubleshoot, I ran the following query: ```sql SELECT amount, CASE WHEN amount > 100 THEN 'High' ELSE 'Low' END AS sale_category FROM sales; ``` This returns all amounts and the correct categories, so my `CASE` logic seems sound. I also tried running my original query with a `HAVING` clause to ensure that I'm filtering correctly, but that didn't work either. I've confirmed there are no NULL values in `amount` and have checked for any potential hidden NULLs in `sale_date`. Is there something about how MySQL handles grouping with calculated fields that could explain this inconsistency? Any suggestions on how to ensure I get both categories in my result set, even when one may have a total of zero? Thanks in advance! For context: I'm using Sql on Linux. Am I missing something obvious? I'm working with Sql in a Docker container on Windows 11.