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What Is a SQL Dialect, and Which one Should You Learn?

Updated on: September 12, 2023

SQL, standard SQL, SQL Server, MySQL, PostgreSQL, Oracle, … You’d like to learn SQL, but you feel overwhelmed with options and you don’t know where to start. We’ll explain what each of these terms mean and what this has to do with SQL dialects.

Diving into the world of SQL dialects can feel like jumping into a deep pool without knowing how to swim. There's a ton of stuff to pick up! And with so many SQL flavors out there, it's easy to get a bit lost. I've been there, trust me.

In this article, I'll be sharing insights and advice that I wish I had when I was starting out. Drawing from my own experience, I aim to simplify the complexities of SQL dialects, offering clarity and direction. Whether you're taking your first steps in the world of databases or seeking to deepen your foundational knowledge, let me assist you in making informed decisions that will shape your SQL journey.

If you've never had a chance to learn any SQL, my suggestion is to start with our SQL Basics course. It's tailor-made for beginners, breaking down complex concepts into bite-sized, easy-to-grasp lessons. Dive in, and you'll be crafting queries like a pro in no time! Plus, this course is based on the SQL standard – if you ever need to switch to other dialects, it's super easy to reference the documentation and adjust to any minor differences.

SQL Is the Language for Talking to Databases

A database is a computer program that can store and process large amounts of data. There are many different vendors of databases. PostgreSQL, MySQL, Oracle, and SQL Server are all database products by different vendors. SQL is the programming language used to talk to these databases, and each database product has its own variant of SQL. We call these variants SQL dialects.

Are SQL dialects compatible? Learning SQL and its dialects is like learning English as a foreign language. If you learn “English,” you’ll be able to talk to everyone who speaks English, but maybe you won’t understand some idioms or regional accents.

On the other hand, if you learn a regional version of English and use its idioms a lot, you may have trouble communicating with someone who speaks another variant of English. If you learn “SQL,” you’ll be able to talk to most databases. If you learn a vendor-specific dialect of SQL, then some of its syntax or functions may not work in a different database.

The SQL Standard

SQL was developed in the early 1980s. At that time, each database vendor had its own version of SQL. These SQL versions varied widely and were incompatible with each other. In the late 1980s, people started working on the SQL standard, a version of SQL that could be understood by most databases. SQL became a standard of the American National Standards Institute (ANSI) in 1986 and of the International Organization for Standardization (ISO) in 1987.

The SQL standard has been revised multiple times since the 1980s, although the core features of standard SQL have been stable since 1992. No database vendor is fully compatible with the standard. Most SQL scripts require at least some changes before being ported to different database systems.

Want to dive into the history of SQL? Check out this article on's blog: The History of SQL – How It All Began. It's a quick read that'll fill you in on SQL's past. Give it a look.

SQL in Big Data and NoSQL Technologies

SQL is used not only in databases these days. Other data processing technologies routinely include SQL as the language to select and process data.

As the amount of data in databases grew, NoSQL databases started gaining popularity. MongoDB, Cassandra, and Redis are among the most widely used NoSQL tools. Interestingly, most of these tools also include the capabilities for retrieving data with SQL. For that reason, some people prefer to call it “Not only SQL” rather than “NoSQL.”

Likewise, Big Data technologies, which allow you to process gigabytes of data in minutes, also offer access to data with SQL. These technologies include Presto, Hive, and Spark, among others.

Database Skills and the Career Market

The demand for professionals skilled in SQL is consistently high. Check out these awesome job platforms and discover how many companies are searching for SQL experts.

As businesses continue to rely on data-driven decisions, the need for individuals who can effectively query and manipulate data using SQL becomes paramount. Whether it's data analysts extracting insights, database administrators ensuring optimal performance, or developers integrating databases into applications, SQL expertise is a common and crucial requirement.

SQL Dialect

Furthermore, mastering SQL opens doors to a wide range of career opportunities. Beyond traditional roles like database developers or administrators, there's a growing demand in fields like data science, business intelligence, and even digital marketing. All these professions leverage SQL to analyze data, forecast trends, and make strategic decisions that drive business growth.

If you're eyeing a future-proof career in the tech or business sectors, SQL is a skill you can't afford to overlook. Its central role in database management and its widespread application across various industries make it a key player in the modern job market.

Which SQL Dialect Should You Learn?

If you just know you need to learn SQL, then you should learn standard SQL. However, if you already know with which specific database you will be working, it’s probably best to learn its SQL dialect and just be aware that different databases may use slightly different syntax. Here are major features of the most popular SQL dialects:


MySQL is often compared to a handy free tool you might find in a toolbox. Imagine having a gadget that doesn't come with a price tag, yet is loved and recommended by many. That's MySQL for the digital world.

People from all over appreciate it not just because it's open-source, but also because there's a large community of users who are always ready to help and share their knowledge. This means if you ever run into a problem or need advice, there's likely someone out there who has faced the same issue and can guide you.

This SQL dialect is versatile and can work on various systems. Whether you have a Windows PC, a Mac, or even a Linux setup, MySQL is adaptable and fits right in. This flexibility makes it a favorite for many, as they don't have to worry about changing their computer setup to use it.

MySQL is designed to handle vast amounts of data, ensuring it's stored efficiently. And when you need to find a specific piece of information? MySQL is like that friend who always knows where they've kept something and retrieves it for you in a flash. It's all about making data management smooth and hassle-free.

Want to learn MySQL? Start with SQL Basics in MySQL or choose to go deeper with SQL from A to Z in MySQL.

Microsoft SQL Server

This one is often just called MS SQL or SQL Server; as you’d guess, it’s made by Microsoft. If you've used Windows or other Microsoft products, this might feel familiar.

One of the standout features of MS SQL is its synergy with business tools. Imagine having several tools that all fit perfectly together, each complementing the other. That's what MS SQL offers to businesses. It's designed to integrate seamlessly with other software, making tasks like analyzing sales data, managing inventory, or tracking customer interactions smooth and efficient. For businesses, it's like having a well-oiled machine where every part works in harmony.

But it's not just about compatibility. MS SQL is like a vault when it comes to safeguarding data. In a world where data breaches are a real concern, having a system that prioritizes security is crucial. What's more, with its ability to compress data, MS SQL ensures that even as data piles up, it doesn't become cumbersome or slow down processes. It's all about efficiency and reliability.

If you've decided to learn MS SQL, check out our beginner-friendly course SQL Fundamentals in MS SQL Server. It's a great place to start, with easy-to-follow lessons and practical exercises.


This one is my favorite database engine and SQL dialect. PostgreSQL is often likened to a Swiss Army knife because of its adaptability. Just as this handy tool has multiple functions for different tasks, PostgreSQL can be adjusted to fit various needs. It's a go-to for many who work with databases because of its flexibility, making it useful for both small tasks and bigger projects.

Using this database will facilitate tasks that require connecting with other databases. Think of it as a friendly neighbor who can easily chat with others in different languages. This ability ensures that data can move smoothly between different systems, making tasks more streamlined.

SQL Dialect

When it comes to organizing different kinds of data, PostgreSQL is a champ. Whether it's simple lists or more complex data like social media posts, PostgreSQL can store and manage it all efficiently. It's like having a super-organized friend who knows where everything is kept, ensuring you can find what you need quickly.

Want to learn PostgreSQL? Start with SQL Basics in PostgreSQL, and then get some practice with the help of SQL Practice in PostgreSQL. It's awesome!

Whatever you choose, learning SQL is one of the best decisions. Each of these SQL dialects has its own strengths, and the best one for you depends on what you need. Think of them like different types of cars: some are better for speed, some for safety, and some for carrying loads. You'd pick the one that suits your journey best.

At, we offer interactive SQL courses in standard SQL, PostgreSQL, MySQL  and Microsoft SQL Server. We plan to add courses for more SQL dialects in the future. You can get access to them with our All Forever Package - it’s the best money-for-value deal!

Even More SQL Terms

You may encounter other SQL-related terms, such as T-SQL, PL/SQL, or PL/pgSQL. Let’s quickly explain what they are.

Transact-SQL, often abbreviated “T-SQL,” is the dialect of SQL used in the Microsoft SQL Server database. Simply put, the SQL Server’s version of SQL has its own proper name. No other database has a proper name for their SQL dialect. If you need to learn T-SQL, we recommend you try our SQL Server courses.

What about PL/SQL and PL/pgSQL? These are languages with which to write your own functions. When you write a piece of SQL code, you usually use the constructions and functions that are predefined in your database. However, all databases allow you to create your own functions or stored procedures. These are called user-defined functions (UDF) and user-defined stored procedures (USP).

UDFs and USPs are usually written by IT professionals: software engineers, SQL developers, and database administrators (DBAs). The language you use to create functions and stored procedures in Oracle is called PL/SQL (a procedural language for SQL).

The language in PostgreSQL is called PL/pgSQL. PostgreSQL’s version was inspired by Oracle’s version; that’s why the names are similar.

If you’re not an IT professional, you probably don’t need to worry about learning how to write your own functions. If you plan to be an IT professional, we have a Writing User-Defined Functions in PostgreSQL course that teaches how to write functions in PL/pgSQL for PostgreSQL.

SQL Dialects: Summary

To sum it all up:

  • SQL is the programming language you use to talk to databases and other data processing technologies.
  • SQL Server, Oracle, MySQL, and PostgreSQL are all different databases that have their own slightly different SQL dialects.
  • The SQL Standard is an official ANSI/ISO document that defines the syntax of SQL. No database is 100% compatible with the standard.
  • Transact-SQL, or T-SQL, is the name of the variant of SQL used in the Microsoft SQL Server database.
  • PL/SQL is the procedural extension to SQL in the Oracle database. It is used to write your own functions and procedures in Oracle.
  • PL/pgSQL is the procedural extension to SQL in the PostgreSQL database. It is used to write your own functions and procedures in PostgreSQL.

The world of databases is diverse and dynamic. Databases like MySQL, PostgreSQL, and Microsoft SQL Server consistently rank among the top choices, highlighting their significance in the tech industry. Each of these databases, or SQL dialects, has its unique strengths and applications, making them indispensable tools for various tasks and industries.

Any of these dialects is a worthy choice to learn. Their popularity not only indicates their robustness but also assures learners of achieving their career goals.

Whether you're aiming to work in a startup or a multinational corporation, proficiency in any of these SQL dialects will undoubtedly be a valuable asset. So, if you're contemplating which dialect to dive into, rest assured that each offers a rich learning experience and a promising path ahead.