What is a practical use of a SELF JOIN?

Problem Statement

Explanation

Self joins let you relate a row to another row in the same table via a relationship like manager_id or previous_id. Alias the table twice so each role is clear. Add indexes on the linking columns for speed.

Code Solution

SolutionRead Only

SELECT e.name AS emp, m.name AS mgr
FROM employees e
LEFT JOIN employees m ON m.id = e.manager_id;

Practice Sets

This question appears in the following practice sets:

CTEs, Subqueries & Advanced Joins

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What is a practical use of a SELF JOIN?

Problem Statement

Explanation

Code Solution

Practice Sets

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Which SQL statement retrieves all columns and rows from a table named employees?

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Master Interviews Anywhere, Anytime

What is a practical use of a SELF JOIN?

Problem Statement

Explanation

Code Solution

Practice Sets

Related Questions

Which SQL statement retrieves all columns and rows from a table named employees?

Which clause filters rows before aggregation and affects which rows are grouped?

What is the default sort order when ORDER BY is used without ASC or DESC?

Which construct is commonly used to paginate results in SQL engines like Postgres and MySQL?

Which predicate correctly checks for missing values in standard SQL?

More from SQL & Databases

Master Interviews
Anywhere, Anytime