Issue with ORDER BY Not Working in MySQL Subqueries
By chance, I discovered that an SQL statement produced different results when executed on different MySQL instances. Problem Description To simulate a business scenario, we create two tables: product_tbl for products and product_operation_tbl for product operation records. The structure and data are as follows: Next, we need to query the latest modification time for all products using the following statement: select t1.id, t1.name, t2.product_id, t2.created_at from product_tbl t1 left join (select * from product_operation_log_tbl order by created_at desc) t2 on t1.id = t2.product_id group by t1.id; From the results, we can see that the subquery first sorts all records in product_operation_log_tbl in descending order by creation time (created_at), then performs a join with product_tbl, thus retrieving the latest modification time for the products. ...