Question

我尝试这样做：从表resource_id中查找items，asset_id和resource_id，并使用它来设置另一个表resource_id中的elements字段，其中还有asset_id和resource_id。

UPDATE t1 SET t1.resource_id = t2.resource_id 
FROM elements t1 INNER JOIN
( SELECT asset_id, resource_id 
  FROM items 
  WHERE resource_id is not null
  GROUP BY asset_id ) t2 
ON t1.asset_id = t2.asset_id;

我收到了非常模糊的信息：

ERROR 1064 (42000): You have an error in your SQL syntax; check the 
manual that corresponds to your MySQL server version for the 
right syntax to use near 'FROM elements t1 INNER JOIN
( SELECT asset_id, resource_id 
  FROM items' at line 2

这是在MySQL 5.6.27中。谁能看到我做错了什么？

谢谢，Max

Answer 1

如错误所示，您的语法错误。试试这个：

UPDATE elements as t1  
INNER JOIN
( SELECT asset_id, resource_id 
  FROM items 
  WHERE resource_id is not null
  GROUP BY asset_id ) t2 
ON t1.asset_id = t2.asset_id
SET t1.resource_id = t2.resource_id

Answer 2

更新元素AS t1，
（SELECT asset_id，resource_id 来自物品 WHERE resource_id不是NULL GROUP BY asset_id ）AS t2 SET t1.resource_id = t2.resource_id 在哪里t1.asset_id = t2.asset_id;

在嵌套查询

2 个答案: