How do you select rows from A that have at least one match in B without duplicating A due to multiple matches?

Problem Statement

Explanation

EXISTS returns true on the first found match and stops. It avoids row multiplication and usually produces an efficient semi-join plan. Distinct can work but may add extra sort or hash steps and is less direct.

Code Solution

SolutionRead Only

SELECT a.id
FROM A a
WHERE EXISTS (
  SELECT 1 FROM B b WHERE b.a_id = a.id
);

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How do you select rows from A that have at least one match in B without duplicating A due to multiple matches?

Problem Statement

Explanation

Code Solution

Practice Sets

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Master Interviews Anywhere, Anytime

How do you select rows from A that have at least one match in B without duplicating A due to multiple matches?

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