mysql - 错误 1054 - 'column' mysql 中的未知列 'where clause'

Question

我在 MySQL 中遇到问题。这是我的代码:

UPDATE ad_copy, (
    SELECT CONCAT_WS(" - ", ad_copy.title, stitle.ttitle) AS `p` 
    from ad_copy, stitle 
    where ad_copy.category = stitle.subcat 
    ORDER BY RAND()) `p` 
set `title` = `p` 
where ad_copy.category = stitle.subcat

我不明白这是什么问题。预先感谢您的帮助

Answer 1

尝试使用 join 更新，您的自定义列通过子查询 (SELECT CONCAT_WS ..) as p 无法识别

UPDATE 
ad_copy a
JOIN stitle  s ON (a.category = s.subcat)
SET a.`title` = CONCAT_WS( " - ",a.title,s.ttitle) 

编辑

UPDATE 
ad_copy a
JOIN stitle  s ON (a.category = s.subcat)
SET a.`title` = CONCAT_WS( " - ",a.title, (SELECT ttitle FROM stitle WHERE subcat =a.category ORDER BY RAND() LIMIT 1 ))