Skill Level Advanced
(bright upbeat music) - [Instructor] In previous episodes of this series, we explored the intricacies of logical query processing and the amazing world of Window functions. And if you haven't watched these courses yet, go watch them now. This course is about conquering relational division challenges. Now, at this point, you're probably asking yourself what is this crazy dude talking about? So let me reassure you that you have encountered relational division challenges before, even if you've never called them by this name. It is easy enough to write queries that return subsets of elements based on a fixed expression filter. For example, find all salespersons who sold something in Q2. This can be solved with a simple workloads. However, find all salespersons who sold something every month of last year is a different story. I'm sure you've encountered similar challenges. For example, find all customers who bought all of our products or find all products that were sold in each and every country. A little light turns on in your head and says, "Oh, that sounds familiar, right?" Don't answer, it's a rhetorical question. Relational division challenges are tricky, but luckily we have three different techniques to conquer them. This course will be action packed. And after a short, theoretical discussion, we will dive right into SQL where we will spend most of our time. I will challenge you to think and write your own queries and I will reveal the methodologies that I use to solve these and similar challenges. The challenges will require a complex logical wizardry and thinking outside the box. I promise you it will be extremely rewarding. Nothing like any other SQL course you've ever seen. You will gain a valuable insight into how SQL work, how to write and troubleshoot queries and how to utilize these insights to solve various types of SQL challenges. Are you ready? Don't answer, it's a rhetorical question.