v.21.6Improvement

Allow CTE in VIEW Definition

Allow to use CTE in VIEW definition. This closes #22491. #22657 (Amos Bird).
Allow the use of Common Table Expressions (CTE) in the definition of VIEWs in ClickHouse.

Why it matters

This feature enables users to write more readable and modular VIEW definitions by incorporating CTEs, which simplifies complex queries and enhances query organization within VIEWs.

How to use it

When defining a VIEW, include the CTE using the WITH clause inside the VIEW's SELECT statement, just as in regular queries. For example:

CREATE VIEW example_view AS
WITH cte_name AS (
SELECT ...
)
SELECT * FROM cte_name;