Correlated Subquery

A subquery that refers to values from an outer query and is evaluated in that context.

What is Correlated Subquery in a relational database?

Correlated Subquery — A subquery that refers to values from an outer query and is evaluated in that context.

SELECT customer_id
FROM customer
WHERE EXISTS (
    SELECT 1
    FROM purchase_order
    WHERE purchase_order.customer_id = customer.customer_id
);

Level: Journeyman · More Database terms at this level

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