SQL & Databases for Web Development
What is backend? How does it work?
The visual part of a website, what the user sees when he visits it is known as the frontend and the interaction that the user has with the website is handled by backend. Backend is essentially a technology that supports the frontend of a website. It offers interactivity with the data stored in the database and offers the users a wholesome experience.
Backend development is a combination of server-side programming languages namely Python, Java, Ruby, PHP etc. and logic-based development which connects, fetches and alters data in the database according to the interplay between the user and the website. Backend development deals with the overall performance and the speed of the website. It continuously runs calls back and forth, retrieving and pushing data from and into the schema.
What is a database? Why is it important for web development?
Before understanding what a database is, we need to understand what exactly data is. Data is a collection of objects ranging from plain simple facts to complex images which provide us with necessary information about a particular entity. A database is an organised and structured collection of this data and a database management system (DBMS) is a tool which manages, organises and interacts with the databases.
There are several different types of DBMS. Four major types are – Navigational DBMS, Relational DBMS, SQL DBMS and Object-Oriented DBMS. The scope of this blog is to deal with SQL Data Base Management Systems but to understand that, a little introduction of Relational DBMS is necessary.
Relational DBMS is essentially a database management system wherein data is stored in the form of relations. On the other hand, SQL DBMS utilizes Structured Query Language (SQL) to perform operations like insert, search, update and delete. It helps in optimizing and maintaining the data within the database.
Web technologies are advancing fast. While you are wondering what ‘web applications’ are, developers have started to transition to ‘progressive web applications.’ Almost every web application on the web requires a database. A shopping application requires a database to interact with the products and the customers.
A dynamic web application such as a news application or a blog requires instant and frequent updating of web pages. For such an application, altering and creating a new HTML page is a tedious task. This is where a database comes into the picture and eases a developer’s life.
Not only retrieval and updating of data, but a database also helps in authentication which is observed in websites having a login and signup functionality. Such websites display customised web pages based on the logged in user. Databases can be a real boon to a web developer if used correctly.
Different types of databases which use SQL
PostgreSQL is a relational database management system which is open source and has been used by developers since a really long time. It has several features which add to the performance of a website. PostgreSQL offers basic to advanced features which makes it a pretty versatile tool.
Popular companies which use PostgreSQL – Apple, Skype, Instagram, NASA, Twitch, Spotify, IMDb, Reddit etc.
MySQL has been ranked as the most popular relational database in existence. It is open-source, extremely easy to use and has been widely accepted by several companies and websites. MySQL is also the first database management system most developers come across. If you are beginner, this is a good DBMS to start with.
Popular companies which use MySQL – Uber, Airbnb, Pinterest, Netflix, Amazon, Twitter, Shopify etc.
SQLite is not exactly a database management system but is a database engine which provides local data storage services for a large number of applications and devices. SQLite is preferred for embedded devices and devices which utilize the concepts of the internet of things. It is also used on desktops as an on-disk file format. If you have a small or a medium scaled website, SQLite will be your savior.
Popular companies which use SQLite – Career Club, Internet Brands Inc., Airgas, Hyatt Hotels Corporation, SAS etc.
Oracle Database is a paid service but is a high-performing and widely available database management system. It is easy to use and offers multiple functionalities to make the developer’s and the user’s job easier. It is an SQL based database management system. However, the syntax differs a little from the other database management systems.
Popular companies which use Oracle Database – JPMorgan Chase, Fiserv, Lockheed Martin, Webster Bank etc.
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Why should one prefer an SQL database?
Databases which use SQL are relational databases. Such databases have a strictly defined schema which cannot change for specific tuples (entries/entities/rows). It is fairly easy to connect to and retrieve data from different tables. NoSQL databases have a huge drawback of duplicity of data. This means that if you have to connect one entry to another, separate space and effort would be required. However, in SQL databases, connections can be made using ‘joins’ and ‘keys’ which makes the job a lot easier.
SQL databases are preferred for situations where the schema has to remain unchanged for a large duration of time. It is also preferred when you require data integrity, data durability, data isolation, data consistency and data atomicity. In short, it can be remembered as ‘when your requirement is ACIDic, use SQL database’. Which means, when you require Atomicity (meaning, you want your request to either be fulfilled completely or not fulfilled at all), Consistency (meaning, all the data in your database should be in accordance with the rules defined in the schema), Isolation (meaning, no two requests overlap each other) and Durability (meaning, a request stays on permanently even if the system fails), SQL database is an excellent choice.
Cases where an SQL database is not preferred
NoSQL databases do not have a well-defined schema which makes it flexible. It means, if you have an application which will require a database that has the functionality of altering the schema based on the entity, then NoSQL databases like MongoDB, DynamoDB etc. are preferred.
NoSQL databases are preferred when speed is a priority, they can access and retrieve large volumes of data within a short amount of time. The null values are handled really well in a NoSQL DBMS. In an SQL based database management system, updating one attribute might take a month to execute if the dataset is humongous, however in a NoSQL database, that can be done within no time and hence becomes cost-effective both in terms of money and computational power, and developer friendly since it saves a lot of time and effort.
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Often developers come across a situation where they are unable to decide which database to prefer, SQL or NoSQL. This is when research about your data and how it will be used on your platform comes into picture. Understand what your application is trying to do and what all features and functionalities do you want to provide to the users.
For analytical, logical and applications requiring high levels of integrity, prefer SQL database management systems. And if your main focus is speed, performance or handling of a large amount of data, you should go for NoSQL database management systems.
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