MySQL不能用select和子查询指定目标表并选择

Question

我有这个疑问：

UPDATE answers AS aa SET aa.question_id=(SELECT q.id FROM question AS q WHERE q.question LIKE (SELECT a.question_prev FROM answers AS a)) 

错误：

mysql cant specify target table

而且无法弄清楚如何编辑它的工作

Answer 1

试试这个，

UPDATE answers a 
     INNER JOIN question b 
      ON b.question = a.question_prev 
SET  a.question_id = b.id 

执行语句前请先备份。