What is SQL Database: In today’s world where every single user of the technology is generating a large amount of data per day.
Therefore to manage this huge amount of data (Database) on the regular basis, we need to make use of some specific Tools or Software.
One of the most popular and resourceful tools which are used for maintaining the gigantic database is SQL.
In this article, we are going to take a deep look at SQL, its working, uses, and commands.
So, let’s start with the actual definition of SQL Database.
Table of Contents
What is SQL Database
SQL stands for Structured Query Language and is pronounced as Sequel Programming Language.
It is based on the ANSI standard for managing the Relational Database Management Systems, which is one of the most popular types of Database Systems and is developed by IBM Corporation in the 1970s.
So, the majority of the Relational Database Management Systems, like – MySQL, SQLite, PostgreSQL, Oracle DB, and many more, uses SQL for maintaining and performing operations over their Data.
If you want to pursue your career as a Database Administrator, Data Analyst or, Data Scientist, then you must have a good understanding of the SQL Programming Language.
Uses or Applications of SQL
SQL is commonly used in the following ways:
- It is used for defining or creating a Database or Table with the help of DDL Command.
- By using different DML Commands, we can easily insert, delete or update the data in our Database or Table.
- SQL is heavily used for retrieving data from the Database using SELECT Command which is a DQL Command.
- We can also control the permission to access the Database with the help of DCL Command, like – GRANT and REVOKE.
Types of SQL Statements
Here are the 3 types of SQL Statements:
1. Data Definition Language – DDL which stands for Data Definition Language is a set of commands that are used for defining or creating a Database or Table.
Some of the DDL commands are CREATE, ALTER, DROP, TRUNCATE.
2. Data Manipulation Language – DML which stands for Data Manipulation Language is a set of commands that are used for inserting, updating, or deleting the data from the Database.
Some of the DML commands are INSERT, UPDATE, DELETE.
3. Data Control Language – DCL which stands for Data Control Language is a set of commands that are used for controlling the permission to access the Database.
Some of the DCL commands are GRANT and REVOKE.
Here are some of the most commonly used SQL Commands that you must know:
1. CREATE – With the help of CREATE Command, you can create a new Table inside the Database.
Example of CREATE Statement:
CREATE DATABASE databaseNAME;
2. INSERT – By using INSERT Command, you can insert one or more rows into the table of your Database.
Example of INSERT Statement:
INSERT INTO TABLE_NAME (VALUE1, VALUE2, VALUE3) VALUES (3, Alex, 22000)
3. UPDATE – This command is used to modify the existing data in our Database.
Example of UPDATE Statement:
UPDATE TABLE_NAME SET VALUE3 = 35000 WHERE VALUE1 = 3;
4. DELETE – If you want to delete or remove any existing data or record from the Database, then you can make use of DELETE Command.
Example of DELETE Statement:
DELETE FROM TABLE_NAME WHERE VALUE2='Alex';
5. SELECT – With the help of SELECT Command, you can operate on any particular Row or Column of a Table in a Database.
Example of SELECT Statement:
SELECT VALUE3 FROM TABLE_NAME;
6. DROP – This command is used to delete a Table or Indexes from the Database.
Example of DROP Statement:
DROP TABLE TABLE_NAME;
How does SQL works on Website
As we know that to make any website, we need to create the Front-End as well as Back-End of that Website.
However, the first part is to create a Database in a Server with the help of SQL.
Then we use the Back-End Programming Languages, like – Python or Java, to connect the client with the server and manage the flow of data between them.
So, the Back-End of a Website uses SQL to access the data stored in the database and show it in the Front-End of a Website.
In this article, we have seen the different Applications of SQL, types of SQL Statements, and some of the important SQL Commands.
At last, we have seen the working of SQL on the Website.
So, hope you like the article on Sequel Programming Language. We also have an article on SQL vs NoSQL which you must take a look at.