I just have a general question that I came up with while doing homework for my database class. I was asked to write a specific query, and when I checked my answer against the posted solutions, it was different. I don't know that much SQL (yet), but I'm pretty sure that my query would produce the result as the given solution. I'm thinking that the solution is just an optimized query. So my question is: Can you have two SQL queries that produce the same result, while one is more efficient/optimized than the other? I just want to know if I'm on the right track regarding the comparison between the two queries.