So, welcome to our Databases course. This is the fourth course in the class and if you have taken all three, you have learned a bunch. There's a lot in this class. If you're two weeks into this class and you didn't take the prerequisite courses, and you're like what are these people talking about? Well, that's what those other courses are. Don't say, "oh why didn't you give me a basic intro to Python?" And the answer is we did that. That's what courses One, Two And Three were. You'll notice that in courses Three and Four, that we're going more slowly through the book. The material's more complex, the lectures take longer to develop. In this we're going to learn Object Training Programming, we're you're going to learn Structured Query Language, and we're going to do a little bit of Visualization. In a way, Structured Query Language is the the biggest part of this class. We're going to learn about Database design, and this is so that ultimately, if you need these Databases as part of a Python program, you're competent in Databases. So, this is more about Database than it is about Python. We're going to learn about, like I said, Database design, One-to-One relationships, Foreign keys, Joins, Select, Delete, Update. I love SQL, Structured Query Language. I think you probably will too. Most beginning students prefer SQL, in a way to Python. Because SQL is a fundamentally different pattern for writing software. In Python you have learned that you got to be very explicit. Like do this, then do that and keep track of this other thing and then check back in that other thing, and add a thing to this other thing, and then print these stuff out and sort them. You're like, do it and there's a bunch of really simple kind of things that you construct. Orders and patterns and loops, and that's what you're good at by now. In SQL you do it all in one one statement. You're like, do this where that happens, pull this other stuff and blah blah, blah, blah, blah, and then magically you get exactly what you want. You write single statement programs that are themselves internally interesting and complex. Like regular expressions. Regular expressions are not essential but SQL in lots of job situations is essential. So I think that you should look forward to learning SQL. It's a fun language. It's different, so get ready for that. Then what we do at the very end is, we do a little bit- bring it all together and do some analysis and visualization and scraping, which is really a preview for the Fifth or the Capstone, where we're just going to do analysis, visualization and scraping. So, welcome to course Four, I hope you enjoy it.