After a decade of working with Structured Query Language, I, Antonello Supino, have created The Zen of SQL. They goal is to summarize my nearly two decades of coding experience into compact guideline that is public and free to use by everyone who writes SQL code for work or passion.
The Zen of SQL: 10 coding principles
- Simplicity Over Complexity – Favor straightforward SQL queries over complex subqueries and joins where simpler alternatives achieve the same result.
- Readability Counts – Write SQL queries that are easy for others to read and understand, using clear naming conventions and avoiding unnecessary shorthand or cryptic syntax.
- Explicit Over Implicit – Be explicit in what you select and where clauses to avoid unintended data selection, ensuring clarity of intent and operation.
- Flat is Better Than Nested – Minimize nested queries and subqueries to enhance the readability and maintainability of your SQL code.
- Efficiency Matters – Aim for queries that optimize performance, such as selecting only necessary columns and using joins and indexes efficiently. Write code that is scalable and idempotent, always.
- Maintenance Should Be a Priority – Write SQL with future maintainers in mind, including appropriate comments and documentation to explain complex logic or decisions.
- Consistency Leads to Predictability – Use consistent formatting, naming, and structuring conventions throughout your SQL scripts to make them predictable and easier to manage.
- Test Your Assumptions – Always test your SQL queries to ensure they perform as expected and handle edge cases and potential errors gracefully.
- Respect the Data – Understand and respect the data you’re querying, including relationships, data types, and underlying assumptions in your database schema.
- Share Your Knowledge – Share effective patterns and learned lessons from SQL scripting with your team or community, fostering a culture of learning and continuous improvement.
These 10 principles aim to foster a more disciplined, readable, and effective approach to SQL programming, focusing on ease of use, performance, and adaptability.
I encourage you to consider how database tools and their design can significantly affect your productivity and data management strategies whether or not you are using AI behind the scenes.