使用来自另一个表的所有数据更新MySQL中的表

Question

我有3个表：ak_class，ak_objects，ak_class_object ak_class：

class_id | class_description | class_name |
1        | some description  | some name  |
2        | some description  | some name  |
3        | some description  | some name  | 

ak_objects: 
object_id | object_description | object_name |
1         | some description   | some name   |
2         | some description   | some name   |
3         | some description   | some name   | 

ak_class_object: 
class_object_id | class_id | object_id  |
1               | 1        | 1          |
2               | 2        | 2          |
3               | 3        | 3          | 

我需要用ak_class表中的ak_class_object和ak_class表中的object_id ak_objects 。

问题是如何更新ak_class表中具有所有ID的class_id（我需要更新，因为当前存在一些错误数据）？ 我正在考虑将其与JOIN一起使用，但我不知道该使用哪个ID来加入它们，因为class_id仅用于更新

UPD：我正在尝试这样做，但是没有用：

DELIMITER $$
DROP PROCEDURE class_object_1$$
CREATE PROCEDURE class_object_1()
BEGIN
DECLARE i INT DEFAULT 0;
WHILE (i < 250000) DO
UPDATE ak_class_object 
SET class_id = SELECT DISTINCT class_id from ak_class, object_id = SELECT DISTINCT class_id from ak_objects;
SET i = i + 1;
END WHILE;
END$$

Answer 1

我正在编写通用语法，根据您的要求更改表名和列名。

update table1 inner join table2
on table1.id = table2.fk_id
set table1.column = table1.columnUpdated