good job on creating this! one thing i'd improve is to have a way to jump to the harder sections without doing the easy ones if you are already good at sql. one other thing is probably showing a sampling of the data so you know what's in the table column names and data formats without being "penalized" by doing a `select * from crew` initially to see the lay of the land. I do that when crafting real world queries all the time to get antiquated with it.