SQL Interview Prep · Lesson

Chaining Multiple CTEs

Building a pipeline of named steps that reference each other.

Why Chain CTEs

Real interview problems rarely fit in one step. Chaining CTEs lets you build a pipeline of named stages, where each stage transforms the output of the previous one. This mirrors how a senior engineer decomposes a hard query into manageable pieces.

Instead of nesting subqueries three levels deep, you write each step once, give it a name, and let later steps reference it.

The Comma-Separated Syntax

To define several CTEs you write WITH once, then separate each named block with a comma. You do not repeat the WITH keyword.

One WITH at the top.
A comma between each CTE definition.
No comma before the final main query.

WITH a AS (
    SELECT customer_id FROM orders
),
b AS (
    SELECT customer_id FROM a
)
SELECT *
FROM b;

All lessons in this course

Writing Your First CTE
Chaining Multiple CTEs
CTE vs Subquery vs Temp Table
Refactoring Nested Queries Into CTEs

← Back to SQL Interview Prep