Lesson 1 - What is SQL?

Most people are looking into changing career to IT due to the Corona virus pandemic, or just wants to learn a new skill to upgrade themselves and increase their income. According to Glassdoor, the national average salary for a Database Developer in the United States is $73,506. Although this takes into consideration, years of experience and/or academic credentials, it is not far off for an entry level position.

One of the most sought-after skill by companies and technical recruiters is, SQL. It is the one skill you NEED to become a Database Developer, Data Analyst, Data Engineer or any role that deals with data storage, manipulation and retrieval. A good Business Analyst must know the basics of SQL to get their job done.

So, what is SQL? SQL stands for Structured Query Language; it is used for Relational Database Management System (RDBMS) and performing operations on data as per business requirements. This programming Language is used to DEFINE, MANIPULATE and CONTROL data.

There are several variations of SQL but we will focus on Microsoft’s proprietary version popularly known as MS SQL Server. MS SQL is mostly associated with Transactions, hence the name Transactional SQL (T-SQL). T-SQL is widely used by banks, hospitals, manufacturing companies, and many other organizations that deals in storing relational data in a table structure.

For example:

NAME			AGE		DOB			
Eugene Nartey		15		10/02/2005		
Oscar Boateng		20		11/05/2000		
John Mahama		35		09/25/1985

There are five types of SQL commands based on its functionality. They are;

· DDL (Data Definition Language)

· DML (Data Manipulation Language)

· DQL (Data Query Language).

· DCL (Data Control Language).

· TCL (Transaction Control Language).

For the purpose of our beginner lessons, we will stick to DDL and DML, which are the two main command types, we will focus on for now. We will delve into the other three types as we progress in our studies.

In our next lesson, we will explain and understand the DDL and DML commands into detail.