错误1442：无法更新存储的函数/触发器中的表

Question

我试图在第三方应用程序中更新数据库。这里是受影响的两个表的架构：

Table 'camera' 
columns: deviceID, connectionState 

Table 'cameraRecording' 
columns: deviceID, recordToVolumeID 

我试过这两个查询，但收到相同的错误。

mysql> update cameraRecording 
     SET recordToVolumeID='STRING' 
     WHERE deviceID 
     IN (select deviceID from camera WHERE connectionState=1); 

ERROR 1442 (HY000): Can't update table 'camera' in stored function/trigger because it is already used by statement which invoked this stored function/trigger. 

。

mysql> update cameraRecording a 
     JOIN camera b 
     ON a.deviceID=b.deviceID AND b.connectionState=1 
     SET recordToVolumeID='STRING'; 

ERROR 1442 (HY000): Can't update table 'camera' in stored function/trigger because it is already used by statement which invoked this stored function/trigger. 

我不是SQL专家，不经常使用它，但我敢肯定，这应该工作。我猜应用程序已经设置了触发器或函数......有没有办法执行这个任务？我读过其他人的其他帖子，其中大部分都涉及到他们试图创建触发器。

Answer 1

你可以声明，然后一个变量使用值？

DECLARE @id int; 
SELECT @id = deviceID from camera WHERE connectionState=1; 

update cameraRecording 
SET recordToVolumeID='STRING' 
WHERE deviceID = @id;