LEFT OUTER JOIN

A join returning every left row and matching right rows, using NULLs when no right match exists.

What is LEFT OUTER JOIN in a relational database?

LEFT OUTER JOIN — A join returning every left row and matching right rows, using NULLs when no right match exists.

SELECT customer.email, purchase_order.order_id
FROM customer
LEFT OUTER JOIN purchase_order
    ON purchase_order.customer_id = customer.customer_id;

Level: Apprentice · More Database terms at this level

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