比较2列和删除不匹配

Question

$db->query("DELETE FROM   probid_auction_media 
WHERE auction_id NOT IN SELECT DISTINCT auction_id FROM probid_auctions");

这是我正在使用的代码，我想要做的是将probid_auction_media的专栏auction_id与probid_auctions的专栏auction_id进行比较，并从probid_auction_media中删除任何不算数学的专栏

Answer 1

你需要括号：

DELETE FROM   probid_auction_media 
WHERE auction_id NOT IN 
      ( SELECT auction_id FROM probid_auctions )

Answer 2

你错过了括号。此外，DISTINCT可能不是必需的：

DELETE FROM probid_auction_media
    WHERE auction_id NOT IN (SELECT auction_id FROM probid_auction)