Question

checkouts

| item_id | user_id |

items

| item_id |

I want a query that will return ALL THE ITEMS with a column that if it exists in checkouts for a particular user_id, it returns a 1. Otherwise it will return a 0.

select * 
from checkouts
right join items on items.item_id = checkouts.item_id
where checkouts.user_id = 10

The problem is that it only returns items that it joins on, not ALL the items.

Any ideas?

Answer 1

What about…

SELECT i.item_id, c.user_id, IF(c.user_id IS NULL, 0, 1) AS extra_column
FROM items i
LEFT JOIN checkouts c ON (c.item_id = i.item_id AND c.user_id = 10)