v.18.14Improvement

Default Join Behavior in SQL Queries

Official CH changelog text
In the absence of JOIN (LEFT, INNER, …), INNER JOIN is assumed. #3147
In ClickHouse, when a JOIN keyword is omitted, the query implicitly assumes an INNER JOIN operation.

Why it matters

This feature simplifies query syntax by allowing users to write joins without explicitly specifying the JOIN type, making the SQL statements more concise while maintaining expected join behavior.

How to use it

Users can write join queries without the JOIN keyword, and ClickHouse will default to performing an INNER JOIN. For example, writing SELECT * FROM table1, table2 WHERE table1.id = table2.id will behave like an INNER JOIN.

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