There are many different types of SQL databases designed for different purposes. Some of the most popular databases also include:
- Microsoft SQL Server.
- Postgres, which is a popular open-source database with a very complete library of analytical functions.
(You can also write SQL within other programming frameworks like Python, Scala, and HaDoop).
Each of these SQL databases may have subtle differences in syntax and available functions — for example, MySQL doesn’t have some of the functions for modifying dates as Postgres. Most of what you see with Postgres will be directly applicable to using SQL in other frameworks and database environments. For the differences that do exist, you should check the documentation.
(Most SQL environments have great documentation online that you can easily access with a quick Google search).