Common Table Expressions

How can we break complex nested queries into clean, readable, reusable modules?

Advanced⏱ 3 Minutes⭐ 490 XP

🤔 THE QUESTION

How can we break complex nested queries into clean, readable, reusable modules?

💡 WHAT IS IT?

A Common Table Expression (CTE) defines a temporary named result set using the WITH clause.

🎯 WHAT IS IT USED FOR?

Readable multi-step transformations, ELT pipelines in dbt/BigQuery/Snowflake, intermediate metrics.

💻 EXAMPLE

WITH high_paid AS (
  SELECT name,
  salary
  FROM employees
  WHERE salary > 100000
)
SELECT *
FROM high_paid;

Practice typing production-grade SQL code for Common Table Expressions.