What is SQL Used For?
SQL is the commonly used acronym for Structured Query Language, the standard language for relational database management systems. SQL traces its origins all the way back to 1973, when it was initially created by a team at IBM to manipulate and retrieve the data stored in their system at the time.
Far from becoming outdated over time, SQL remains the primary language for communicating and interacting with databases, used by a variety of heavyweights including Oracle, Sybase, Microsoft SQL Server, Access, and others. While many of these systems have their own proprietary extensions tailored to their specific needs, SQL remains the structure on which these databases are powered.
So what is SQL used for specifically? How has SQL continued to prove its usefulness over the past several decades? This guide will walk you through the basics of SQL, what you can hope to do with it when you master it, and the best ways to start learning SQL for yourself.
Why was SQL created?
SQL was created for a simple, specific purpose: to query data stored within a relational database. Why is this so important? A language that efficiently manipulates, filters, and retrieves data from a database can allow individuals or companies to:
- Search for trends among user behavior, to help develop branding and outreach or fix existing UI gaps
- Actually sort and collect the mountains of data accumulated by an app or web page, to answer operational or research questions
- More easily search for single use cases or customers based on key categories or columns, without having to manually go line-by-line
- Better package and present important data, whether for resale opportunities or to present as evidence for research or academic papers
- To go beyond simply collecting and displaying information, as you might with Microsoft Excel - unlike simple spreadsheets, SQL databases can process millions upon millions of cells of data
SQL offers important flexibility to its users by supporting distributed databases - databases that can be run on several computer networks simultaneously. SQL serves both enterprise and academic needs, and can be used on both individual computers and corporate servers. Further driving its continued adoption is affordability - as database technology has continued to progress, SQL-based applications are no longer cost-prohibitive for casual users.
Why Should I Learn SQL?
While most major programming languages have a variety of functional uses that have led to their widespread adoption, there may be no more universally important language to learn than SQL. Here are a few reasons why:
- Collecting, sorting, and manipulating data is essential to nearly every business with a significant web presence these days. Knowing SQL is essential to perform these functions and help business managers make more informed decisions to compete.
- In conjunction with its importance, the widespread need for experienced database managers has led to significant demand (and similarly, rapidly rising salaries) for individuals who are well-versed in SQL and database operations.
- Unlike the variety of front-end or back-end languages (like Python or Ruby, for instance), SQL is largely the industry standard even decades after its creation. While some alternatives are beginning to emerge, knowing SQL can be a more widely applicable skill than learning a single language for creating a web app or online game.
Examples of SQL in Action
So what do these various benefits and applications of SQL actually look like in a real-world application? Here are some examples across a variety of industries and market verticals where SQL plays a key role:
- Perhaps you run a subscription-based news or service business. If you wanted to search for every client who chose to upgrade to a specific monthly subscription plan AND filter them by location, SQL capabilities allow for that level of specificity when filtering and sorting data.
- Music apps like Spotify and Pandora are powered by complex, frequently-used databases responsible for storing everything from customer preferences to music genres and categories. SQL-powered databases power these apps’ ability to store vast libraries of music files and albums by various artists, operate this data to find what the user is looking for, and generate relevant suggestions and similar content to improve user experience.
- Similarly, social media sites like Facebook and Instagram are equally powered through storing a diverse library of user info (in this case, personal information from user profiles and posts) and making that info efficiently sortable for generating search results that are predictive and relevant to user needs.
- In academic settings, SQL databases are also essential to modern research and observations in various scientific fields. This is especially true for highly technical research fields like astrophysics or molecular biology, where complex and precise data are essential to supporting research conclusions and develop new technologies or innovations based on those results.
Common Elements of SQL Language
So what does SQL actually look like? What are the characteristics that make this language so universally relied upon for such a long time? In a simple sense, SQL is based on an array of key elements that make up the general structure of the language. To make things easier for SQL developers, all necessary language commands in the corresponding database management systems are normally executed through a unique SQL command-line interface (CLI). These elements include:
- Clauses - the clauses are components of the statements and the queries
- Expressions - the expressions can produce tables or scalar values, which consist of both columns and rows of data (similar to what you’d see in an Excel sheet)
- Predicates - these elements specify conditions, which can be used to limit effects of statements and queries or change the program flow
- Queries - a query will retrieve data, based on a given criteria. Queries allow users to manipulate the database with a specific end-goal or desired data set in mind.
- Statements - statements allow SQL developers to control transactions, program flow, connections, sessions, or diagnostics. In most database systems, the SQL statements are utilized for sending queries from a client program to an external server where the databases are stored. The server processes the SQL statements and returns replies to the client program in response to these queries.
In addition to these common elements, SQL is also largely driven by commands. While there are numerous specific commands for creating targeted queries or returning specific sets of data, some example commands an SQL developer often uses include:
- CREATE DATABASE – to create a database
- CREATE TABLE – to create tables
- SELECT – to find/extract some data from a database
- UPDATE – make adjustments and edit data
- DELETE – to delete some data
While these seem obvious, SQL queries offer the ability to combine commands to return a very specific and targeted set of data. The more complex and intensive a database is, the more the commands will reflect this need for nuance.
What Are The Most Popular SQL Database Systems?
Oracle is the primary name to know among SQL database systems, as it is the most widely used of all of the systems. Particularly popular for data warehousing and online transaction processing, the Oracle database has an ever-growing number of use cases each passing year.
Microsoft SQL Server
SQL Server is Microsoft’s enterprise SQL database management system. This database runs on all major versions of Windows operating systems, which is part of the reason for its sizable user base. In addition to web servers that are run on Windows, Microsoft SQL is often used for consumer software needs.
The most popular choice for small business owners and startups, mostly because it doesn’t have a license fee, MySQL is an open-source database system. This makes it obviously useful in conjunction with open-source programs and applications as well.
The main competitor to MySQL, PostgreSQL is also an attractive open-source option for startups and small businesses looking to avoid paying licensing fees. Unlike some of the other SQL servers that significantly change standard SQL syntax for their own purposes, PostgreSQL adheres pretty closely to the standard, making it easier to read and understand than others.
How Do I Learn SQL?
Like any programming language, the trick to learning SQL is starting with the fundamentals. SoloLearn’s SQL Fundamentals course offers the ideal combination of resources for any beginner looking to learn the language. The course includes:
- Tutorials and mini-lessons on over twenty different essential topics for learning, understanding, and using SQL for your own projects
- The ability to unlock achievements and score points by completing fun, relevant quizzes and coding challenges as you progress through the class
- The opportunity to collaborate and network with thousands of other coding learners and beginning programmers to build skills and solve problems together
- SoloLearn’s comprehensive Code Playground provides a space for practicing with actual code and building your own “starter projects”
Database managers are in high demand, from small startups to the biggest companies around the world. Get started with SoloLearn’s SQL Fundamentals course today, and begin your path toward mastering databases and data manipulation.