Although I primarily work with MySQL/MariaDB these days on back-end web development projects, I am studying Oracle SQL with the end goal to become certified. I recently watched a great YouTube video and decided to try my hand porting over the Oracle SQL queries to comparable MySQL for a learning exercise. This blog post details the queries I came up with for the end results. Continue reading for some fun recursive CTE’s using the SUBSTRING() character function and interesting output display variations.
(more…)MySQL
MySQL Searched CASE Expression – with examples
During many decision-making phases in programming code (conditional logic), there are times execution depends on several different factors. Multiple conditional tests are powerful and constraining, oftentimes requiring more than one test to be passed in order for program flow to proceed.
For MySQL (and standard SQL in general) the CASE expression is used for IF/THEN/ELSE conditional logic. The post, MySQL Simple CASE Expression – with examples, covered Simple CASE queries which are essentially equality tests. MySQL Simple CASE is but one variant of 2, with the other being a MySQL Searched CASE Expression. A MySQL Searched CASE Expression can have multiple conditional tests in each WHEN clause. These conditional tests can be AND/OR comparisons, BETWEEN value range tests, subqueries, IN() operators, and more. Continue reading to see examples of the MySQL Searched CASE Expression…
MySQL Simple CASE Expression – with examples
Programming logic is foundational in any application or piece of software. Without it, software wouldn’t really do much of anything. Everything happens off of choice. In the end, some truthy or falsy value is what makes stuff work. For IF/THEN/ELSE logic in standard SQL, there is the CASE expression. There are 2 variations of the CASE Expression: Simple and Searched. In this post, I cover the Simple MySQL CASE expression with example queries…
MySQL Column Aliases using the AS keyword
Be it running reports or displaying data in some other visualization, SQL SELECT column expressions should be meaningful and understandable. To provide those valuable query results, SQL Developers, use a multitude of available functions, adjacent columns, or other means not readily apparent to end-users. All that being said, the column names often suffer the most as far as readability is concerned, taking on long function call names or other combined expressions. But, as luck would be on our side, there is an easy fix and that is aliasing columns using the AS keyword. Although AS is optional – in this particular context – I err on the side of readability and use it when aliasing SELECT column expressions.