postMay 27, 2026

SQL CTE — make complex queries readable

#sql#cte#intermediate

sql

WITH daily_sales AS (
  SELECT
    DATE(created_at) AS day,
    SUM(total) AS revenue
  FROM orders
  GROUP BY DATE(created_at)
)
SELECT day, revenue
FROM daily_sales
WHERE revenue > 1000
ORDER BY day;

A CTE (Common Table Expression) is a named temporary result set defined with the WITH keyword. It exists only for the query that contains it. CTEs make complex queries readable by breaking them into named, logical steps.

Without CTEs, complex queries become deeply nested subqueries that are hard to read and impossible to debug. With CTEs you build the query in stages: first compute the daily totals, then rank them, then filter the top three. Every intermediate step has a name, like a variable in regular code.