In the past few months, I have learned the importance of writing clean, readable, and efficient SQL queries. They are essential for integrating information from different tables.
However, writing complex queries from scratch can be time-consuming, especially when you frequently use them for analyzing your data. To address this need, SQL offers a powerful construct, known as Common Table Expression.
In this article, I am going to explain what a Common Table Expression is, why it’s useful, and demonstrate its application through examples. Let’s get started!
Table of contents:
- What is a Common Table Expression?
- Setting up DBeaver and Database
- Three simple examples of CTEs
What is a Common Table Expression?
A Common Table Expression (CTE) is a temporary result set that simplifies complex queries, making them more readable and maintainable. It works by breaking a complex query into smaller, more manageable pieces — essentially building on sequential, modular subqueries. It doesn’t just limit on managing complicated queries. It can also be…