SQL Tutorial for Business Analysts
SQL is an important skill for every entry level business analyst. In this SQL tutorial for business analysts, you will learn the basics of SQL including database fundamentals, SQL structure and SELECT command. This is a 3-part tutorial series.
Introduction to SQL
Structured Query Language (SQL) is used to interact with databases. A database is nothing but a software system to store data for later usage. If you don’t save the data, you can’t use it later.
For example, when you register on a website as a user, the website saves your data (like name, user id and password etc) so that you can login anytime after your successful registration.
When you enter your userid and password in the login box, it checks that data with the saved information and if the entered data is found and matched, you are allowed to enter the website and use its features.
SQL is the language, which programmers and IT professionals use to interact with database systems.
Formally, a database is known as a Database management system or relational database management system (RDBMS). Oracle, SQL Server and mySQL are some of the popular database systems.
A database system has many components, which are associated with storage and management of data. A table is specifically used for storage of data whereas other components are used for related purposes.
A table is a combination of rows and columns (think of Microsoft Excel worksheet). To identify columns in Excel, we give it a name, similarly in database systems, we give names to table columns to identify them.
See the STUDENTS table below, it has named columns to identify “WHAT IS WHAT”, sounds logical?
The STUDENTS table has 4 columns and 5 rows. Each column representing a specific aspect of STUDENT like name, date of joining etc. This table stores the details of STUDENTS, who have joined courses at Techcanvass.
How do you save data into table? If you want to know when did “Ramesh Chandra” joined, how can you do it?
This is where SQL or Structured Query language comes into picture. SQL provides mechanism (known as Commands) to accomplish the tasks of saving, querying and performing other operations with the tables and other components of a database.
The most important commands are SELECT, INSERT, UPDATE, DELETE. There are many other commands like CREATE TABLE, DROP TABLE etc. SQL provides commands to deal with each of the components of database.
You can refer to the diagram above named “Components of a database”. If you are not planning to become a SQL developer, you should only focus on learning the following commands:
- CREATE TABLE