I tried:
UPDATE giveaways SET winner = '1' WHERE ID = (SELECT MAX(ID) FROM giveaways)
But it gives:
#1093 - You can't specify target table 'giveaways' for update in
FROM
clause
This article seems relevant but I can't adapt it to my query. How can I get it to work?
Based on the information in the article you linked to this should work:
update giveaways set winner='1'
where Id = (select Id from (select max(Id) as id from giveaways) as t)