SQL · Joins and set operations

self join

Joins a table to itself, usually through two aliases.

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Syntax

from employee e join employee m on …

Example

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WITH people(id, name, manager_id) AS (VALUES (1, 'Ada', NULL), (2, 'Linus', 1))
SELECT p.name, COALESCE(m.name, '—') AS manager
FROM people p LEFT JOIN people m ON m.id = p.manager_id;

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self join

Example

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