How to learn SQL: a step-by-step guide (with definition)
By Indeed Editorial Team
Published 24 May 2022
The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.
If you're a data analyst, data engineer, database developer or administrator, learning SQL can help you advance in your career. SQL allows you to create and maintain databases and information solutions. Developing SQL skills is a good starting point when planning to learn more complex programming languages, such as R and Python. In this article, we discuss what SQL is, look at how to learn SQL and review the benefits of learning this programming language.
What is SQL?
Structured query language (SQL) is a standard programming language that's used to design, search and maintain relational databases. These databases contain tables filled with rows of data, with each column representing a different category of data. SQL allows data professionals to search through these large datasets and extract specific information for analysis. Some other SQL functions include:
adding, updating and deleting data rows
generating tables and other database projects
modifying database tables and indexes
performing calculations and filtering data
retrieving information for transaction processing
joining elements from different data tables together
How to learn SQL
Below, you can find out how to learn SQL:
1. Determine why you want to learn SQL
Consider why you want to learn SQL before looking at the language's theory and how to use it in practice. You're likely to face challenging moments when studying so it's good to have a clear idea of why you're doing this as a source of motivation. Some reasons to consider learning SQL include:
getting a specific job in data development and engineering
gaining access to company datasets easily and on-demand
learning more than just the basic Excel VLOOKUP function
working with bigger datasets proficiently
reducing repetitive tasks by creating repeatable data processes
building a specific dashboard or answer a certain query
2. Learn basic SQL syntax
Start by learning basic SQL syntax, including the functions SELECT, WHERE, FROM, HAVING, ORDER BY, LIMIT and GROUP BY. Remember that the code's order is different from the order of execution. This ensures that you learn appropriate query structures and execute them properly.
Every query requires a SELECT and FROM statement to determine which columns you want to retrieve information from. For this reason, it's recommended that you start with them. The list of SQL demands is short so try and get through them as quickly as possible. Doing so allows you to deal with real SQL-related problems sooner which acts as a motivator.
3. Watch tutorial videos
Tutorial videos allow you to work on interactive guided projects that put your new SQL skills into practice. These videos may require you to query databases and analyse them for answers. Working on guided projects can help you to overcome the complexity of building your own project at an early stage while still allowing you to learn through gaining practical experience.
Try and work your way through the videos on your own and only seek guidance or answers when you're lost or unsure what to do next. As you grow more confident, you can then begin working on guided projects with increasing independence. Try to avoid copy and pasting from the tutorial video so that you become adept at writing code yourself. Some tutorials to consider include Microsoft's SQL Database Fundamentals tutorial and the interactive courses offered by Codecademy and SQLZOO.
4. Consider an SQL class
Taking a class is a great way to supplement your own learning. There are several courses available, both online and in-person, that teach you basic SQL demands and more complex skills. In-person classes can provide you with practical training and are an effective way of preparing you for advanced SQL topics. For instance, you can learn how to use SQL in production. Some of these courses also provide you with certification upon completion.
5. Seek useful resources
Before you start working on your own projects, consider bookmarking some useful SQL resources that can aid you in further developing your SQL skills. You can also ask other professionals for resource recommendations they've used in the past. SQL learners use a variety of resources, some of which include:
GitHub: This software allows you to share your SQL projects and browse other people's code. It serves as an open-source community where you can build, ship and maintain software.
/r/SQL: Reddit has its own page dedicated to SQL users. Here, you can filter posts to find the ones most relevant to you and stay up-to-date with community trends.
Stack Overflow SQL questions: This is a platform where you can post SQL questions or issues and receive feedback from others. It also shows you the questions others have asked so that you can see what advice they received for the same problem.
6. Install a free SQL database
Before you can start practising SQL on your own, install an open-source database on your laptop or computer. This is necessary to start writing and running queries using your own data. Most databases are free to install and are compatible with most operating systems. Downloading an SQL database also allows you to practise in your own environment and at your own pace.
7. Practise with data
After installing the database, you can practise working with your own data. Some professionals choose to work with real data from the company they work for as it's relevant to their job and field. Alternatively, you can download publicly available data from several online platforms, including freeCodeCamp and Kaggle. It's also possible to convert downloadable data in CSV format into an SQL format where necessary. Simply look for conversion programs online and choose the most appropriate result.
8. Build your own SQL projects
After acquiring your data, you can start working on your own SQL projects. For this step, you can refer back to why you want to learn SQL to determine a suitable project type for you to work on.
Try to work on projects you're passionate about and which align with your career prospects. For instance, if you want to perform Excel tasks more effectively, you can learn how to perform the same tasks on SQL to improve your efficiency. It's also helpful to choose projects that relate to what you do in your regular job so that you can easily apply your newly acquired skills to real-world scenarios.
9. Advance your projects
Finally, consider working on more advanced projects as you develop your experience with SQL. Rather than working on the same projects every time, create different ones so you can continue to grow your skills and challenge yourself. Make sure that, with each new project, you're learning at least one new skill or ability. For instance, instead of creating entirely new projects, you can consider reviewing old ones and giving them a new level of complexity.
Additionally, to continually advance your projects, you can consider making a checklist of all the things you want to achieve with SQL. Then, order them according to how difficult they are to execute and tackle them one by one. Once you feel competent executing a task without guidance or second-guessing yourself, you can check it off the list and start on a new task. This way, you can track your progress with advancing your SQL skills over time.
Benefits of learning SQL
Learning SQL offers several advantages for data professionals who are looking to advance their careers. Some of these benefits include:
Employers look for individuals with SQL skills
Employers in data-related industries typically seek individuals with SQL skills. These skills are also applicable to marketing and web development, making them pertinent to several industries. Employers find these skills valuable because they allow individuals to analyse data effectively and act on their findings.
Once you've finished learning SQL, you can pursue professional certifications. These can give you a competitive advantage when applying for jobs and can demonstrate your programming skills to prospective employers. Pursuing professional certifications also demonstrates your commitment to your career in data analysis.
It's typically easier to audit and replicate information in databases with SQL when compared to standard spreadsheet tools. Most companies use SQL-based databases and management systems to store information, so learning it can boost your employability and give you more flexibility over the roles you can pursue. SQL also gives you the flexibility to start learning other programming languages.
With SQL, you can work with large datasets quickly and navigate them for necessary information. Since SQL is a written language, each query you enter is repeatable and easy to understand once you know the basics. There are also no hidden formulas to discover or use, as is the case with Excel and its VLOOKUP function.
Please note that none of the companies, institutions or organisations mentioned in this article are affiliated with Indeed.
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