Unexpected NULL values in SQL Server after applying multiple filters in WHERE clause
After trying multiple solutions online, I still can't figure this out. I'm working on a SQL Server 2019 query where I'm trying to retrieve user information along with their latest order details. However, I'm working with unexpected NULL values in my result set when I apply multiple filters in the WHERE clause. Here's the SQL query I've written: ```sql SELECT u.UserId, u.UserName, o.OrderId, o.OrderDate FROM Users u LEFT JOIN Orders o ON u.UserId = o.UserId WHERE u.IsActive = 1 AND o.OrderDate >= '2023-01-01' AND u.Region = 'North' ORDER BY o.OrderDate DESC; ``` The intention was to get active users from the North region who have placed orders since the beginning of this year. However, I'm noticing that some active users are returning NULL for the OrderId and OrderDate fields. I checked the `Orders` table and confirmed that these users indeed have orders. I've tried modifying the query by changing the `LEFT JOIN` to an `INNER JOIN`, but that filters out users without orders completely, which isn't what I want. Also, I’ve verified that there are no discrepancies in the `Region` column values and checked for any leading/trailing spaces that might be affecting the filter. I'm also aware of potential NULL handling issues with SQL, but I'm not sure how they relate to my specific case. Is there a reason why my filter on `OrderDate` might be causing these NULLs? What would be the best approach to ensure I still retrieve users without orders along with their details? Any insights would be greatly appreciated! I'm working on a API that needs to handle this. I'd really appreciate any guidance on this.