Perform basic and advanced queries in SQL on a company database

Structured Query Language, or SQL, is a powerful programming language used to manage and manipulate relational databases, or RDBMS. Three key points about SQL are:-

1. SQL is used to store, retrieve, and manipulate databases.
2. It is a standard language supported by many databases, such as MySQL, SQL Server, Oracle, and PostgreSQL.
3. SQL includes commands for data definition (DDL), data manipulation (DML), and data control (DCL).

In my last code review of SQL basic commands, I covered basic commands using the student dataset, and that post can be read here:- https://medium.com/@tracyrenee61/learn-basic-sql-commands-using-the-student-table-710ebbc62329

In this blog post i intend to expand upon the SQL’s basic commands by using the company database, the code of which can be found here:- https://www.giraffeacademy.com/databases/sql/creating-company-database/

I completed a SQL tutorial hosted by freecodecamp.org, and the code in this post is a review of what was covered in the course. I found the course to be quite informative and it taught me that I have much to learn before I am proficient in SQL.

The database is composed of five tables, being:-

1. Employee