What is SQL and how to get started with it?

In our day to day life, we use numerous applications, gadgets and devices. An enormous amount of data is being generated every second. SQL provides a standard way to tackle this kind of data. Through the medium of this article ill explain you the concepts of what is SQL and its evolution.

The following topics will be covered in this article:

1. 1. 1. Problem with the Traditional File Systems

      2. Evolution of SQL

      3. What is SQL?

      4. Advantage of SQL

      5. SQL in REAL-TIME

Problems with the Traditional File System:

Since the very beginning of the computing era, data storage was already became one of the major concerns. Previously, we used to store the data in a file-based system and this lead to mismanagement of the data. Even though it seemed to be neatly organized it had its own internal flaws. Below I have listed a few of them:

• Data Redundancy

  It exists when the same data are stored in different places in our computer system. In File System, there is no active check for the duplicate files. This will increase the structure size and also leads to a lack of security features. Because of this, the file system is highly vulnerable in nature.

• Limited Data Sharing and Lack of Security

  Data sharing and security are closely related. Sharing data among multiple geographically spread users introduces a lot of security risks. In terms of spreadsheet data and other documents, the inbuilt file system programs provide basic security options, but they are not always used.

  In terms of the creation of data management and reporting programs, security and data-sharing features are usually difficult to program so they are normally omitted in a file system environment. Such features include effective password protection, the ability to lockout parts of files or parts of the system itself, and other measures designed to safeguard data confidentiality. Even when they are used, they are insufficient for robust data sharing among users.

• The Difficulty of Getting Quick Answers

  Another important problem in traditional file environment system is the difficulty of getting quick answers because it needs more Adhoc queries and more programming for new reports. So, we can’t make the decision very fast.

• Data Dependence

  In File System, files and records are described by a specific physical format that is coded into the application by programmers. If the format of anyone record was changed, then we need to make sure that all the remaining records format is updated. This information has to be updated in the system also. Any changes in storage structure or access methods could greatly affect the processing or results of an application.

Because of all the above-mentioned drawbacks and as well as few other limitations, there was a need for implementing a new technique, so the SQL was born.

Evolution of SQL

SQL was developed in the 1970s at IBM Corporation, Inc., by Donald Chamberlin and Raymond F Boyce. It was initially called SEQUEL but was later changed to SQL. The reason for this change of name is SEQUEL was the name of the UK based Engineering company. In SQL the data is stored in the form of relations. This relation theory was suggested by Boyce and Chamberlin.

Only after certain years, SQL language was made publicly available. The first company to release an altered version of SQL was Relational Software, Inc. (now Oracle) and it called it as Oracle V2. After that American National Standards Institute (ANSI) and the International Standards Organization have deemed the SQL language the standard language in relational database communication. Today, SQL is accepted as the standard language for Relational Database Management System.

So, What is SQL?

Structured Query language (SQL) is pronounced as “S-Q-L” or sometimes as “See-Quel”  which is the standard language for dealing with Relational Databases. Let us take more of a real-life example to understand what exactly SQL is.

If two persons want to communicate with each other then they have to use certain language which is understood by both of them. If we consider these two people, one as a user and the other as a database, then that language which is used for communication between these two is called SQL. Similarly, how a language has the grammar and various rules on how it should be used, even SQL has its own directives. 

SQL is effectively used to insert, search, update, delete, modify database records. It doesn’t mean SQL cannot do things beyond that. In fact, it can do a lot more other things as well.

Now that we have understood what is SQL, let us look at its processing capabilities:

• DDL (Data Definition Language) provides SQL commands for defining relation schemas, deleting relations and modifying relation schemas.
• DML (Data Manipulation Language) provides a query language based on both the relational algebra and tuple calculus.
• The embedded DML is used for general-purpose programming languages.
• DDL includes commands for defining views.
• DDL commands are used for specifying access rights to relations and views.
• SQL provides integrity checking.

Let us look at some Basic Queries that are most popular in SQL.

• Create a Database: The syntax for this is

Create Database database_name;

• Delete a Database that has been already created.

Drop Database database_name;

• Create a Table in a Database

Create Table table_name;

• Delete table that previously exists

Drop Table table_name;

So if you want to learn more SQL queries then have a look at the article on SQL Basics which I have written. This article will help you to get started with the SQL

Advantages of SQL

Since we have understood what SQL is all about, now its time to know its advantages.

• SQL has well-defined standards

As it says, Developers of SQL has mentioned how exactly each and every query has to be written. There is no room for ambiguity when it comes to writing a query. The standards have to be followed.

• It is easy to learn

Yes, SQL is a language that is used to work with the database. Since SQL has a large user base as well as a well-defined standard, for a beginner it is really easy to learn.

• In SQL we can create multiple views

This is one of the unique and early features that SQL came up with. View is nothing but creating a virtual table. A virtual table is a temporary table for certain use. By doing this we can protect the integrity of the data. SQL cannot only create a single view but can create multiple views.

• SQL queries are portable

It means we can execute the SQL queries in one system and execute the same in another system, without changing the format. But the condition is that the environment setup of these systems has to be the same. Else the query won’t be executed

• It is an Interactive Language

The main purpose of SQL is to communicate with the database. We can write complex queries to fetch the results from the database and these queries can be easily understood by anyone.

Now, lets now see some of its real-time application.

SQL in REAL-TIME

Since SQL is a language that is used to operate on the database, we need to look at the bigger picture of the data management industry. Here if I say Database, it includes SQL language as well. The database is used in different verticals like Online stores, health care providers, clubs, libraries, video stores, beauty salons, travel agencies, phone companies, government agencies, etc. Now let’s consider some real-time examples for the use of SQL and Database.

• FINANCIAL SECTOR

Managing money, assets, shares etc in a real-time is a tedious task. SQL and Database technology is helping the financial sector to achieve its primary task. SQL queries can be also used to check the fraudulent activities.

• EDUCATION SECTOR

Database systems are frequently used in schools, colleges and in universities to store and retrieve the data regarding student details, staff details, course details, exam details, payroll data, attendance details, fees details, etc. There is a lot amount of inter-related data that needs to be stored and retrieved efficiently.

• HEALTHCARE SECTOR

In hospitals and medical institution maintaining data related to doctors, patients and staff is a huge task. Effectively coordinating among these three has to be handled seamlessly. With the help of SQL and Database, this industry has gained a lot.

• RETAIL INDUSTRY

In retail industry customers data has to be managed effectively. There is no scope for error when it comes to handling the data. With the instigation of SQL and Database system, the retail industry can not only secure the data but also can get the real-time analysis.

This brings us to the end of this What is SQL article. I hope you understood the Evolution of SQL in depth.

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