Nine Reasons Developers Should Learn SQL

Written on June 21, 2011 by Jeremiah Peschka in SQL Server

Let’s face it, there are a lot of cool new things you could be learning right now. It seems like there’s a new technology coming out every 12.8 seconds. Why the hell would you want to spend your free time learning a crufty old language like SQL? My reasons, let me show you them.

It’s portable

Computer science students are taught hundreds of techniques and theoretical constructs while they earn their degree. A lot of that information isn’t directly applicable in day to day programming tasks, but it introduces students to fundamental constructs that they can move between platforms – they have a common vocabulary and tool kit that they can take with them wherever they go.
Although every database vendor implements their own extensions, with every new version the vendors are moving their databases to be in line with the ANSI/ISO SQL standard. Standards compliance, while tricky, makes it possible to take your knowledge from platform to platform. If you learn SQL, you’ll be prepared to move from one database to another.

It never changes

My good friend and business partner jokes that he became a DBA because SQL hasn’t changed in 35 years. This is, largely, true. Vendors have implemented their own extensions that eventually make it into the SQL standard, but the core of SQL doesn’t change. Once you understand the basics of SQL and relational theory (it’s not that hard), you’ll find that you can continue to build on that knowledge and add features and functionality that you were relying on other tools or developers to implement.

It’s an easy place for performance gains

There are only a few places to implement performance gains in an application – the presentation layer, the application layer, and the storage layer. Let’s face it, your code is already well written and well tuned; getting any performance gains there is going to be like getting blood from a stone. The database, on the other hand, is an easy place to make a few simple changes (add an index, change a query slightly) and see tremendous performance improvements. Having spent a considerable portion of my career as an application developer staring at a profiler, I can attest to this. It’s possible to pry performance improvements out of application code, but modern frameworks and toolkits are typically so well-written that the database is usually a better place (read as easier place) to find low hanging fruit for performance improvements.

It’ll make you a better developer

The Pragmatic Programmer challenges developers to learn a new language a year; not because the landscape is constantly changing but because learning new languages exposes developers to new paradigms. There are different ways of thinking about problems that can lend themselves well to different solutions (I’ve recently learned a lot from diving into functional programming). Learning SQL will teach you to think in sets rather than iteratively. In the long term, this will change the way you think about working with data and lead to improvements in your database code.

Improve communication across teams

Have you ever tried to talk to someone who spoke your language but spoke a wildly different dialect? Communicating across a language barrier can be difficult outside of work, but it can be outright maddening when the success of a project depends on it. Learning SQL will give you a leg up when you’re communicating your goals to the DBA team. They won’t have to decipher your meaning and you can tell them exactly what you need. In the end there will be less miscommunication, things will get done faster, and you’ll no longer be “that frustrating developer.”

Job security

I hate to say it, but learning SQL may mean that you get to keep your job when Ted in the next cube gets canned during layoff season. The more skills you have and the more job functions you can perform, the more valuable you become to your current employer (and to a future employer). If you can work with the database team and the development team, you’re now a valuable asset that both teams depend on for success.

It’s really not that hard

Contrary to popular belief, SQL is not a difficult language to learn. It’s a different way of thinking, that’s for sure, but it’s not difficult. There are only a handful of commands, operators, and data types documented in the ANSI/ISO standard. While vendors may add their own features, there’s a compact core of knowledge that you can learn and apply everywhere you go.

Know when it’s not appropriate to do something in the database

The database is a phenomenal tool for solving many problems, but it’s also a horrible tool for solving even more problems. To put it another way: you probably shouldn’t be digging a trench with a hammer. By learning and understanding SQL, you’ll be able to make better decisions and move poorly performing code out of the database. In fact, you’ll be able to spot these problems before they’re even problems.
Once you understand SQL, you’ll have a much better grasp on the limitations of an RDBMS. You’ll know which portions of an application can safely live in a database and which will need to be moved further up the stack to a different layer. Some data validations should live with the data, some shouldn’t. Understanding how SQL works will help you determine which rules should remain in the database.

Simplify troubleshooting

Live applications are notoriously difficult to troubleshoot. The more complexity and layers that are involved, the more difficult it is to troubleshoot an application. A good understanding of SQL makes it possible to rapidly isolate problems that do exist in the database. To put it a different way: understanding SQL makes it easy to locate the problem in one of many different layers of your application.