In recent years, with the gradual transformation of digital technology, trillions of bytes of data are generated every second. Some experts rightly say – “Data is the new oil!” ”。 User-generated data comes in many forms – this data is generated through social media browsing, binge-watching movies, shopping through online portals, online banking transactions, etc.
So what’s the use of such a large amount of data? This data is organized according to the needs of the business to carry out targeted advertising that entices customers to view and purchase their products. This data is used to analyze customer behavior in order to improve the user experience, thereby increasing sales or improving the quality of service.
However, the generated data is highly unorganized and needs to be cleaned before being analyzed by experts. In addition, storing such a large amount of data is another major task that needs to be addressed. Today, there are several big data solutions that help companies store, organize, and analyze large amounts of data. But what about already structured data from websites? These include your login/sign-up details, credit card details, user profile details, online purchase history, and more. This data can be reused by the company the next time you visit their website. To reuse it, it’s obvious that they need to store it somewhere safe.
How do I learn SQL? Large server nodes are set up on cloud or physical machines with huge databases that store such data. Now, multiple types of databases can be used for different purposes. To manage different types of databases, you need certain database management skills. Let’s start by discussing the different types of databases, as well as the SQL learning roadmap.
Tiered databases
This type of database has a tree structure, and they have a parent node, and each parent node has several child nodes that are linked to the branch. The parent node represents the high-level data, the child node represents the low-level information, and the branch represents the relationship between these nodes.
Object-oriented databases
This type of database has key components such as classes and objects. An object can be defined as a live instance of a class. They hold records or actual data to be stored. Classes have functions, methods, or variables that define what you want to do with those objects or data.
Web databases
This type of database has a network structure. It supports many-to-many relationships between nodes and is designed to solve the problem of hierarchical databases.
Relational databases
In this type of database, the data is stored in a record or table, with columns that define the data type and rows that contain the actual information. Tables can form relationships with other tables based on conditions.
The most common type of database used across organizations to store data in an organized, secure, and robust manner is a relational database. Relational databases are highly scalable and flexible when it comes to accessing certain sets of information. SQL or Structured Query Language is a programming language that is used to query relational databases and find out records or information from tables.
SQL Study Guide: What is SQL?
As mentioned earlier, SQL is a programming language that can be used to query data in relational databases. You can create, update, modify, delete, and perform other operations on tables in a relational database. SQL is a declarative language, or in other words, it is a procedural language. This means that instead of specifying what type of data the user can specify, instead of specifying it and getting the data.
Problems with legacy file systems
SQL Learning Roadmap: Before the invention of SQL or other databases, data was stored in a file system and had many uses associated with poor data management. Although we believe that file systems appear to be well-organized, they still have several flaws when it comes to storing, accessing, and modifying contiguous amounts of data. Let’s discuss a few of them.
Data redundancy
Data redundancy means that the same information is stored in one or more places, resulting in unnecessary storage space usage. In the case of file-based databases, there is no way to find out the duplicate files. In addition, as a result, the file system is exposed to security risks and information leakage.
Data dependency
In the file system, there is a specific structure that needs to be followed. If we change the format of any record, we need to update the format of all the data that depends on it. In addition, changes in the file system-based database structure have a significant impact on the performance of the application.
Data Sharing
Data sharing is a major problem in the file system as it can lead to significant security risks. Even if we use security measures such as encrypting files, password-protecting them, locking a part of them, etc., these measures are not enough to ensure complete security.
For all of the above reasons, there is an urgent need to create a new form of data storage to solve all these problems.
The importance of SQL
Let’s take a look at a few key points that make SQL such a popular query language.
Popular with professionals
It is a universally adopted expert, and professionals don’t hesitate to turn to SQL when it comes to processing and organizing data. All popular open-source and free databases support SQL query information.
Easy to learn
The syntax of SQL is similar to a simple natural language, and it is very easy to learn compared to the complex syntax of other programming languages such as Java, C++, etc.
Process large amounts of data
Compared to excel and spreadsheets, SQL can easily handle large data sets with minimal administrative effort.
Better insight into data sets
To retrieve useful insights from your data, you need to understand it better. SQL allows you to use commands to get relationships between datasets to better understand them.
Standardization
SQL is a query language that is standardized for both ISO and ANSI. It’s very stable, there are no major updates in syntax, and once you learn it, you don’t need to pay much attention to the newer version.
In-demand skills
If you want to work in fields such as data science, machine learning, database management, data analytics, etc., SQL is a common skill that is in high demand in the job market.
Why learn SQL?
How do I learn SQL? Let’s go through a few key points to give you an idea of why SQL is one of the most important skills that will keep you up to date with the latest skills and technologies.
- It has a number of processing functions defined as collections, such as data definition language (create, change, and delete patterns), data manipulation language (update, insert, delete, retrieve tables), data control language (revoke permissions or grant them).
- It allows you to perform integrity checks on your database and normalize your database to eliminate data redundancy and other issues associated with filesystem-based databases.
- With a single line of command, you can retrieve highly filtered data as well as multiple records.
- Once you master the language, you can use complex queries to better understand your data.
- It has a simple syntax, is highly scalable, offers high security, and has a large community.
- It’s interactive, highly portable, can create multiple views of tables for work and experimentation, and has well-defined criteria.
Careers at SQL
SQL Study Guide: In data-centric organizations, a large number of jobs and careers require SQL as a skill. These organizations seek SQL professionals who can apply their analytical thinking to SQL to better gain insight into large amounts of data. If you are a candidate with a knack for working with data and manipulating it, then you should definitely seek a career in SQL programming. SQL-related job markets can be found in cloud-based organizations and organizations that use on-premises databases.
Educational Requirements
- The qualifications that recruiters seek in SQL professionals can vary from company to company. This largely depends on the ROI, customer requirements, type of work, etc.
- Basic educational qualifications include a bachelor’s or master’s degree in computer science, engineering, IT, or even a professional program in the IT field.
- Other certifications, such as database developer, administrator, designer, architect, and more, will add color to your portfolio and give you an edge over thousands of other candidates.
- Experience with PL/SQL, ETL, etc would be beneficial.
Job Position
- SQL Server is the third most popular database server, and millions of professionals are currently working in different roles that directly or indirectly require SQL as a skill.
- The top career paths for SQL include- Database Administrator, Business Intelligence Professional, Data Scientist, Database Developer, Database Tester, ETL Developer, BI Application Developer, Big Data Specialist, Cloud Database Engineer, Database Migration Engineer, etc.
Salary
- The average salary of a SQL professional largely depends on the career path he chooses. In general, professionals with more than 5 years of experience working with SQL earn a higher average salary than a recent graduate.
- According to a 2018 report by payscale, the average salary for a SQL developer in the United States is about $65,000, $85,000 for a senior SQL developer, $100,000 for a senior database administrator, and the average salary for a production DBA can be as high as $130,000.
Prerequisites for learning SQL
To start learning a query language like SQL, you must understand the following areas.
- Database management system.
- DBMS concepts such as normalization, ACID attributes, transactions, etc.
- ER diagrams, relational models, and all things about relational databases.
In addition to this, one should have good analytical skills and understand how to store data in an organized relational database in order to generate useful insights from complex queries via SQL.
Note that you don’t need to worry even if you don’t have a background in computer science or IT and don’t have prior knowledge of database management systems. We’ll provide you with all the resources, courses, tutorials, and documentation, and you’ll learn concepts from basic to advanced later in this article. So, stick with it until the end.
SQL Learning Roadmap: How Do I Install SQL?
Let’s see how to install SQL Server on your Windows machine, which will help you write SQL queries such as creating databases, tables, inserting data into tables, modifying and updating data, etc.
You can download Microsoft SQL Server from the official Microsoft website.
The current latest version is SQL Server 2019. Note that Microsoft allows you to download two free versions of SQL Server. They are the Developer and Express versions. MS SQL Server Developer Edition has all the required features, but the problem is that we can’t use it for production. However, another free version called MS SQL Server Express Edition is available for production but has limited features. For those who want to learn SQL, it’s best to start with the Developer Edition.
Press the Download Now button. This will download an executable file that you can run to install SQL Server. Once the installation begins, it will ask you to choose one of three different installation types – Basic, Custom, and Download Media. The Basic option automatically selects all the basic packages you need to get started with SQL Server. The customization option will allow you to choose your own packages, and the download media option will allow you to download all the packages and then install them on different machines.
We’ll choose the basic option. After that, accept all the license agreements, choose the installation location, and install the server. After a successful installation, you can click the Connect Now button to start executing the query.
IDE for SQL
How do I learn SQL? An IDE, or integrated development environment, is a graphical tool that allows you to manage all your application-related files and use useful packages, autocomplete features, syntax highlighting, and more to make your development experience better.
While you can create and manage databases and tables directly from the command line itself, using an IDE is always helpful in getting a bird’s-eye view of all databases, queries, tables, and other components. In fact, some IDEs have helpful sections that explain the basic commands and their usage. All you have to do is fill in the text fields, select the various pre-formatted commands, click the “OK” button, and you’re done. It’s as simple as that. In addition, some IDEs allow you to back up and restore databases and tables.
Therefore, before you get into SQL, it’s always a wise decision to choose an IDE that meets your needs. The following is a list of the top IDEs that you can use to write complex SQL queries.
DBeaver
DBeaver is an open-source, Java-based database IDE. It’s free to use and has powerful features that give you a smooth development experience.
Features-
- It allows you to export the table to a CSV file and dump, restore the table.
- It lets you save the most commonly used SQL commands. You can load these saved commands later for other projects.
- It also has several color themes.
- It has a session management tool.
- It allows you to compare two database tables and their structures.
- Executed queries are beautifully displayed in a separate interface.
- It allows you to edit the cells of a database table and submit them graphically.
phpMyAdmin
PHPMyAdmin is a feature-rich, HTML-based, open-source tool that can be used to manage databases.
Features-
- It allows you to manage users and permissions.
- It can support multiple languages.
- It allows you to create and edit queries and columns for result rows.
- You can save your query for later use.
- The IDE is highly configurable and can hide or show tables, comments, character sets, timestamps, and more.
- You can create backups of your databases, convert them to CSV files, import SQL dumps, and more.
- It allows you to manage multiple servers.
- You can use QBE to create complex queries.
Adminer
Adminer can be used as an alternative to PHPMyAdmin. It’s web-based and supports a large number of plugins, allowing you to work with multiple databases, such as Oracle, SQLite, and more.
peculiarity–
- Connect to a database, create a new database, and more.
- You can print the schema of the database even if you have a foreign key to concatenate them.
- You can set and manage user permissions and permissions, and even change them as an administrator.
- The help section is pretty good; You can display variables that have reference links to documents.
- You can easily manage partitioning of tables and events.
Online compiler
If you don’t want to go through the hectic process of downloading SQL Server and installing them, downloading and installing the IDE, you can always use one of the many online compilers available on-demand. Some of the most popular online compilers for SQL are -mycompiler, tutorialspoint, and JDoodle.
A roadmap for learning SQL
SQL Study Guide: Previous knowledge of database management concepts and relational databases may be helpful. However, you don’t really need to know them to get started with SQL. Here’s a complete roadmap to help you get started with SQL.
- Start by learning the basic concepts of database management, such as databases, transactions, relational models, normalization techniques, tables, different keys in schemas, and more.
- After you’ve learned the basics of database management, you can move on to the basic topics and concepts of SQL. Some of them are –
- SQL syntax, data types, variables, and more.
- Select, Where, And, Or, Not, Order By, Commands.
- Insert, update, delete commands.
- Min, Max, Count, Average, Sum, commands.
- Like, in, between, top, group by, command.
- Connections, such as internal, external, left, right, full, self-connected.
- SQL has, exists, any, all, case, null, and so on.
- SQL Database-related commands, such as create, delete, backup, and so on.
- SQL table commands, such as create, alter, update, drop, and so on.
- SQL constraints, such as not null, unique, check, default, auto-increment, etc.
- SQL keys, such as primary, unique, foreign, and so on.
- SQL advanced concepts such as views, triggers, functions, PL/SQL, injection, hosting, and more.
- Once you’ve mastered all of the above topics, you’ll be ready to start creating databases and tables and executing the commands you’ve learned in theory.
If you follow this roadmap, you will learn the concept of databases as a SQL comma, which will surely help you to have a good understanding of the whole database management concept, which will help you gain an edge over other candidates and thus get a good career DBMS.
You can also read the SQL Cheat Sheet for a quick overview of the roadmap.
SQL courses and tutorials
SQL Learning Roadmap: Here’s a list of online courses and tutorials that you can use to learn SQL in a more detailed and practical way. Using these courses will provide you with clear guidelines and pathways as well as a number of projects to enhance your portfolio and start your career.
The Ultimate MySQL Bootcamp: From SQL Beginner to Expert – Author Udemy
- This is one of the most detailed lessons you’ll ever come across. To get started with this course, you don’t need to have any knowledge of databases, SQL, or MySQL. This is complete beginners. However, if you have previous programming experience, you will be able to understand these concepts better.
- It will take you through practical projects to understand detailed concepts that will help you learn them better. After completing this tutorial, you can easily develop and build complex databases.
Features-
- You’ll be able to create, use, and interact with existing databases.
- Writing complex SQL queries will be a piece of cake for you.
- You’ll build a web application using MySQL and Node.js.
Resources – 20 hours of video, 141 articles, 4 resources, certificates.
Price– INR
8640 Rating– 51,134 with a rating of 4.6.
Excel to MySQL: Analytical techniques for business specialization
- This is a specialization offered by Duke University through the Coursera platform. The specialization consists of 5 courses. With the help of this course, you’ll be able to transform data into valuable insights and drive change in business processes by analysing key metrics.
- You’ll learn how to use Excel and SQL to manage big data and analyze such large amounts of data. You’ll also learn data visualization techniques using Tableau.
Features-
- You’ll be able to manage big data using MySQL and Excel.
- You’ll learn to visualize data with Tableau.
- You will master data analysis.
- You’ll create models, predict, design, and perform analysis.
- You will work on a real-life project.
Resources – 5 courses, approximately 7 months of content.
Price– INR 3576 per month.
Rating– 4.6 out of 18,019 ratings.
Introduction to Databases – EdX
- This is EdX’s self-paced course that covers all database and SQL-related topics from beginner to advanced. It is taught and led by industry experts and will help you build database programming skills to improve your knowledge. Through their lectures, you’ll learn how to build SQL databases; You will learn the basics of databases and more.
Features-
- You’ll learn how to create SQL queries to perform CRUD operations in a database.
- You’ll learn concepts such as referential integrity and integrity constraints.
- You’ll draw data models such as ERs and apply SQL queries to patterns based on those models.
- You’ll be able to learn processes, triggers, functions, and more.
- You’ll learn about concurrency control.
Resources – 4 months of content, 6-8 hours per week. Articles, video tutorials, quizzes.
Price- INR 33144
. Rating – 4.5.
Check out some of the top SQL certifications that will help you take a leap in your career in 2021.
Popular free resources for learning SQL and DBMS
In addition to all of the expensive online courses and tutorials we’ve discussed above, you can also take advantage of some of the top free resources available online to learn SQL and DBMS concepts in detail. Some of the top free resources are –
DBMS online resources
- DBMS for GATE Exam – TutorialsPoint
- DBMS Tutorial – by JavaTpoint
- DBMS Tutorial: A Complete Crash Course on DBMS – Edureka
SQL online resources
- SQL Tutorial – W3Schools
- Introduction to SQL: Querying and Managing Data by KhanAcademy
- SQL Tutorials – Provided by TutorialsPoint
Learn SQL from documentation
In addition to all the online paid and free courses and tutorials mentioned above, you can also refer to the official documentation provided by Microsoft that will help you learn SQL in the best possible way. The documentation provides detailed information about the commands and concepts in the most detailed way, explaining the concepts and their usage from an unbiased point of view. Check out Microsoft’s official SQL Server tutorial.
Top SQL projects for beginners
The best way to learn any programming concept is to start with a project, not just master the theory and grammar. Projects help you find solutions to problems you will face in the real world. They will give you a deeper understanding of these topics; It will help you apply your theoretical knowledge to create great products and significantly boost your resume and portfolio.
Projects are a validation of your skills. As a beginner, you should start with small projects with fewer features and modules so that you don’t give up when something goes wrong. After you’ve built a few small projects, you can add extra functionality to those projects or build a new complex project.
Here’s a list of the top beginner SQL projects.
Library management system
You can create a simple web application that connects to a SQL database, where you can store book-related details such as author, price, publication, content, genre, and so on. You can create a portal where students, researchers, and faculty members can use their ID cards to register books within a specific period of time, impose fines if books are not returned within the time frame, create payment portals, create another database to store the details of user profiles, etc.
Online retail applications
You can create another web application that allows users to create profiles, display item lists and price details, supplier details, and more, allowing them to add products to cards, add credit card information, make purchases, track deliveries, and more.
Rail Booking System
You can create a platform that allows users to book train tickets and has features such as user login, payment functionality, display of a list of trains between locations and their times, number of seats available, train routes, and more.
Hospital management system
You can work with a clinic or create a standalone app that allows patients and doctors to communicate and consult with each other via video conferencing, prescribe medications, pay fees, manage appointments, schedule calls, display medication lists and their information, and more.
Human Resource Management System
You can create another app that allows small companies and organizations to manage their human resources. It tracks their employees and their performance, including pay scales, departments, responsibilities, scheduling, assigned projects, and other important information.
Check out our guide to the top SQL projects.
Best SQL Certifications
SQL Study Guide: After you have a detailed understanding of theoretical and practical concepts, the next step is to create a portfolio to highlight your SQL skills in an interview. You’ve completed some projects in SQL, and the next step is to get accredited and verifiable certifications from official SQL vendors. Some of the accredited SQL certifications are –
- MTA: Database Basics
- MCSA：SQL Server 2012/2014
- MCSA: SQL 2016 database management
- MCSA: SQL 2016 database development
To get more information about these certifications and other top certification courses, you can visit this guide to learn how to advance your career with the top 5 SQL Server certifications.
SQL Interview Questions
How do I learn SQL? After getting ready with all the theoretical and practical concepts of SQL, projects, certifications, and more, it’s time to prepare for the big day. You can now confidently move on to the next and final step and start preparing for SQL-related questions to do well in your interview. When you attend an interview, always remember to back up all of your theoretical answers with practical and real-life scenarios.
Here is a list of the most common SQL interview questions.
- Question: What is the difference between the traditional database model and the relational database model?
- Question: Is it possible to inject PL/SQL in code snippets for SQL?
- Question: What does DML mean and explain some of its operations.
- Problem: Explain connections and different types of connections.
- Problem: Explain the concept of ACID in SQL transactions.
- Question: Can you explain the terminology dateadd used in SQL?
- Question: The fundamental difference between MySQL and SQL.
- QUESTION: IS IT POSSIBLE TO USE BOTH A WHERE CLAUSE AND TRUNCATE?
- PROBLEM: DEFINE COMMIT
- Problem: Distinguish between tables and fields in SQL.
You can get the full list of SQL QNAs here.
Summary of SQL learning roadmaps
- In this guide, we started with a basic introduction to SQL and databases, and we also discussed the different types of databases. We’ve already discussed what SQL is and the problem with traditional file systems. We also discussed the importance of SQL and why it remains a hot job in the current market.
- Then, we went through a few reasons why you should study SQL in 2021 and discussed several career opportunities in SQL. We also discussed the prerequisites for learning SQL and installing SQL Server on a Windows machine.
- Next, we discussed some of the top IDEs and online compilers that you can use to improve your SQL programming experience. We quickly discussed a detailed roadmap that can help you learn SQL as well as some paid and free courses and tutorials online. We also discuss how to learn SQL in the best way to effectively use documentation.
- After that, we discussed how to improve your portfolio by doing projects, earning accredited and verifiable certifications, and improving interview preparation with a curated list of SQL interview questions.
We hope that with this detailed guide, you will have a complete and accurate SQL learning roadmap for 2021.
