Welcome to the first in a series of videos and posts on learning spatial SQL. This will focus on learning the core elements of SQL, and in the name of not reinventing the wheel, there are already such great resources to learn SQL.
What you need to know
Here are some of the top things you should focus on when learning SQL. Of course, there are more but this is a good base list to choose from.
- WHERE, AND/OR, (NOT) IN, BETWEEN
- Handing NULL data
- Using SQL functions
- Aggregations – MIN/MAX/AVG/SUM/COUNT and GROUP BY
- CASE WHEN
- CTEs or Common Table Expressions
Courses for SQL
Mode SQL Course
The Mode SQL course is a great tool that breaks down every aspect of SQL from end to end for a beginner with absolutely no experience up to those looking for more advanced tutorials. It also allows you to practice with sample data in their platform and has some programming challenges at the end.
I really like Learn SQL which has a few different options. You can select a course on a very specific topic like window functions or joins, run through monthly practice sessions, or complete courses. You don’t need to set anything up and you can run all your queries and sessions right from your browser.
Practice SQL Online
Here are some of the best resources to practice your SQL skills online.
Practice real SQL use cases and questions from interview questions from a variety of companies all from your browser. Stratascratch is just like Leetcode, but built for and by data scientists and analysts. You can also practice Python and other languages too.
This is a practical and contained SQL tutorial that allows you to practice a range of basic concepts all in your browser. Simple and easy to get started.
Reference guides for SQL
You always need to look things up, and outside of the code docs (which I definitely recommend becoming familiar with), these are great tools for great quick look-ups as you are working with SQL.
This is a very comprehensive toolkit for referencing SQL functions and checking and referencing quick guides and proper usage.
W3 Schools has so many resources for a lot of languages, and SQL is no different. You can quickly find any reference on the site and then see the structure, usage, and actually run the code in the browser too.
Advanced SQL from Taylor Brownlow
This series of 5 posts is one of the best set of really comprehensive posts on advanced SQL topics such as common table expressions, dates, joins, window functions, and user-defined functions. These are incredibly well written so I recommend them for beginners and as refreshers for advanced users.
Spatial SQL Cookbook
This is a quick reference guide I put together for some spatial SQL code snippets.
Learn SQL Cheatsheets
Everyone loves a cheat sheet! These are an amazing visual reference for more simple and advanced topics.
Data by Danny SQL Challenge
Data by Danny is one of the best resources for SQL online! Follow him on LinkedIn and make sure to check out his resources page. There are free resources, code challenges, and a link to his super comprehensive course called the 8 Week SQL Challenge.