Interview Question

What is recursive CTE?

A recursive CTE grows a result from a base term until no new rows are produced.

💡 Concept ✅ Quick Revision 🗃️ SQL

Answer

A recursive CTE can refer to its own result to process hierarchical or iterative data. • It has a non-recursive starting term. • A recursive term repeatedly uses rows produced so far. • The query must contain a condition that eventually stops producing new rows.

💡 SQL Example

WITH RECURSIVE numbers(n) AS (VALUES (1) UNION ALL SELECT n + 1 FROM numbers WHERE n < 5) SELECT n FROM numbers;

Result

1 2 3 4 5

⚡ Quick Revision

A recursive CTE grows a result from a base term until no new rows are produced.