When do you use a SELF JOIN?

Problem Statement

Explanation

A SELF JOIN uses aliases to treat the same table as two roles. It helps express parent child links or supervisor employee relations. Aliases are mandatory so the columns from each role can be referenced unambiguously.

Code Solution

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SELECT e.emp_id, e.name, m.name AS manager
FROM employees e
LEFT JOIN employees m ON m.emp_id = e.manager_id;

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When do you use a SELF JOIN?

Problem Statement

Explanation

Code Solution

Practice Sets

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When do you use 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