SQL Server query with LEFT JOIN not returning expected rows when filtering with WHERE clause
I've tried everything I can think of but I'm working with an scenario with my SQL Server query where I'm performing a `LEFT JOIN`, but it seems that the `WHERE` clause is filtering out rows that I expect to see. I'm using SQL Server 2019. Here's a simplified version of my query: ```sql SELECT a.id, a.name, b.order_id FROM Customers a LEFT JOIN Orders b ON a.id = b.customer_id WHERE b.order_date > '2023-01-01'; ``` The intention here is to get all customers along with their orders, but only for those orders placed after January 1st, 2023. However, when a customer has no orders, the result shows those customers as well, but the rows are completely omitted in the result set if they have no orders. If I remove the `WHERE` clause, I get all customers as expected, but once I add it back, customers without orders are not included at all, which defeats the purpose of using a `LEFT JOIN`. I tried using a `COALESCE` function to handle the null values in the `WHERE` clause: ```sql WHERE COALESCE(b.order_date, '1900-01-01') > '2023-01-01'; ``` This approach didn't yield the expected results either; it still filtered out customers without orders. Can someone explain how I can modify my query to include all customers while still filtering orders based on the date? I expect to see customers with `NULL` `order_id` when they have no orders. Thanks in advance for your help! What am I doing wrong? How would you solve this? I recently upgraded to Sql 3.10.