Question

我使用以下查询来更新mysql中的users表

update users set user_likes = 
(CASE WHEN like_by_users NOT LIKE '%user_name%' 
AND dislikes_by_users NOT LIKE '%user_name%' 
THEN (user_likes +1) ELSE user_likes END)
WHERE post_id = '2221'

这对我来说很好，但我也想像这样更新likes_by_users

likes_by_users = CONCAT(likes_by_users,' ','user_name')

我试过这样做

update users set user_likes = 
(CASE WHEN like_by_users NOT LIKE '%user_name%' 
AND dislikes_by_users NOT LIKE '%user_name%' 
THEN (user_likes +1), likes_by_users = CONCAT(likes_by_users,' ','user_name')  
ELSE user_likes END)
WHERE post_id = '2221'

但它根本不起作用。我不想再次检查条件但是如果上面提到的条件为真，那么它应该更新两个列（user_likes）和（likes_by_users）不仅（user_likes），如果条件为false，那么它不应该更新任何列。

Answer 1

您可以借助WHERE子句来完成此操作。

UPDATE `users`
SET `user_likes` = `user_level` + 1, `likes_by_users` = CONCAT(`likes_by_users`, ' ', 'user_name')
WHERE `post_id` = '2221'
AND `like_by_users` NOT LIKE '%user_name%' 
AND `dislikes_by_users` NOT LIKE '%user_name%'

Answer 2

尝试这样

update users
Set user_likes = IF(like_by_users NOT LIKE '%user_name%' AND dislikes_by_users NOT LIKE '%user_name%',(user_likes + 1), user_likes),
  likes_by_users = IF(like_by_users NOT LIKE '%user_name%' AND dislikes_by_users NOT LIKE '%user_name%', CONCAT(likes_by_users,' ','user_name'), user_likes)
WHERE post_id = 2221

如何在SQL查询中基于一个条件更新2列

2 个答案: