Overview

[MUSIC] 0:00 Hello and welcome to your next exciting step in your SQL journey. 0:04 I'm Andrew a database user, lifelong learner and teacher here at Treehouse. 0:09 In this course we're going to build on that foundation of 0:14 knowledge you've already acquired. 0:17 You should be familiar with performing simple select statements and 0:19 filtering using WHERE clauses. 0:23 If you don't understand what any of that means you should check out the course 0:25 prerequisites, I've listed them in the teachers notes below. 0:29 SQL databases can store massive amounts of data, getting the information you want and 0:32 presenting it in a human readable and digestible way is a necessary skill for 0:39 anyone needing information from a database. 0:44 Let's think of a couple of ways that you'd want to retrieve data in a database. 0:48 Imagine you wanted to present products to a user of an online store 0:55 alphabetically by name. 0:58 You'd do this by retrieving that information from the database, 1:00 in a specific order. 1:04 Or you might want to display all products by price 1:05 from the least to the most expensive, for example. 1:09 Again, you'd request the data in a specific order. 1:12 If you run a news site, 1:16 you may have thousands of news stories going back tens of years. 1:17 Your readers don't want all of those stories, so 1:21 you'll only request the latest articles from the database. 1:24 Limiting what you retrieve is very helpful, 1:27 especially when your database holds lots and lots of data. 1:30 Data can be inconsistent, especially when end users are involved, so 1:34 being able to manipulate strings of text and make it consistent is super important. 1:39 Maybe you want to make all emails lowercase and last names uppercase. 1:45 Instead of just looking at individual rows in a table 1:50 you may want to group them together and ask questions about them. 1:53 For example, you may want to count all products bought on a certain day or 1:57 maybe you want to get the total amount of revenue generated by sales. 2:02 You can even get the maximum or minimum review ratings for a product. 2:06 Grouping data like this is called aggregation. 2:11 Then there's reporting tools for dates. 2:15 SQL code provides tools for creating dates and searching by dates. 2:17 These come in handy when you're looking at ranges of dates. 2:22 For example, say you wanted a report showing all sales in the last seven days. 2:25 Using SQL, you simply retrieve all records from seven days ago to today. 2:31 This kind of dynamic reporting is very useful. 2:36 This same SQL query can be run everyday to return just the latest results. 2:39 In this course we're going to take a look at all the different coding tools 2:46 that the programming language of SQL has to offer. 2:50 By the end of this course you'll be able to generate database results suitable for 2:53 reports, or even a dynamic website. 2:58 Whether you're an analyst, scientist, marketeer, support staff, or 3:01 developer, this course is for you. 3:04