MySQL Data Types & Joins

Progress keeps going with MySQL, and made a nice improvement to the blog today too.

MySQL Progress

Today we picked up with learning about different data types you might use in a database. We focused on string types CHAR and VARCHAR; number types DECIMAL, FLOAT, and DOUBLE; and temporal types DATE, TIME, and DATETIME. Then we did logical operators for comparison using regular operators < > <= >= && || and keywords like BETWEEN, NOT BETWEEN, IN, NOT IN. All of this came together when we looked at case statements which bring even more logic into evaluating and displaying data.

After that we started working on joins: making data tables connect to each other and storing it efficiently to avoid redundancies. We did one-to-many relationships today and next time pick up with many-to-many relationships.

All of the notes are in this gist for future reference.

RSS Feed For Hexo Site

I also added RSS to this blog with the hexo-generator-feed npm package. It was probably the easiest part of this whole site. 😂 After publishing it I subscribed to myself in Feedly and it looks great! Way better than the output the old Jekyll site had, although admittedly I could have edited that, whereas I have nearly zero control over how the Hexo feed is generated. So glad it works!

Other Stuff

I also made some small improvements to the site: portfolio image links are now clickable with a stealthy hover transition, and I fixed the navigation links which kept bouncing off to the GitHub Pages url.

Up Next

Getting my head around table relationships and then we start building stuff! Since it’s moving so quickly I decided to finish this course before going back to CS50.