Reference

WPDB Power Tool Reference

WPDB Power Tool Reference with useful information for WordPress, Database and PHP development.

MariaDB MySQL Functions – Includes all functions used in the WPDB Power Tool as well as ones commonly used for UI applications
Useful Quick Key combinations – Keyboard key combinations that get things done faster
$wpdb Object usage Examples – Actual example usage code for the WordPress $wpdb object.

Addition references for above may be found at:
MariaDB Built-in Functions for a complete list of all MAriaDB functions and how to use them.
WordPress Developer $wpdb Class for a good reference of the full details of the $wpdb object.

This is reference for the three main topics. That being MySQL/MariaDB, the $wpdb WordPress object and quick key combinations to make editing faster and easier.

You may also find practical application Tutorials on this site that cover the use of the WPDB Power Tool at:
Building a Stored Procedure – Goes over the basic parts of a stored procedure and building a simple Stored Procedure with a simple select in the WordPress posts table.
INSERT Stored Procedure Tutorial – Part of a series of tutorials that teach the use of the WPDB Power Tool as well as how to build an INSERT stored procedure for any application. This tutorial series covers all four aspects of database queries.
SQL Basics Tutorial – Goes over the basics of TABLES, SELECT, INSERT, DELETE and UPDATE statements with a companion Stored Procedure Tutorial for each of the INSERT, SELECT, UPDATE and DELETE statements.
Stored Procedure Tester Tutorial – This tutorial goes over the use of the Stored Procedure Tester allowing you to test various scenarios prior to implementing in code in order that the data passed to the code is scrubbed prior to being passed to the application. You can also test for SQL Injection vulnerabilities as well with this tool.