我不知道为什么我会收到此错误：-

Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.
The statement has been terminated.

我正在尝试运行此查询：

ALTER TABLE Test1 NOCHECK CONSTRAINT ALL
ALTER TABLE Test2 NOCHECK CONSTRAINT ALL


UPDATE Test1 
SET ID= '05f6c6b4-63ff-45b2-a5e2-920d5dce3e45' 
WHERE ID = '05e6c6b4-63ff-45b2-a5e2-920d5dce3e45'; 
UPDATE Test2 
SET ID = '05f6c6b4-63ff-45b2-a5e2-920d5dce3e45' ,
SpecID = NULL ,
RefLastName = 'Dummy' ,
RefFirstName = 'First Name' ,
RefMiddleName = NULL ,
RefPhone1 = '111444444' ,
RefPhone2 = '2121222' ,
RefFax = '222222' ,
RefEmail = 'xxxxxxx@hotmail.ca' 
WHERE 
RefID = '05e6c6b4-63ff-45b2-a5e2-920d5dce3e45'

ALTER TABLE Test1 WITH CHECK CHECK CONSTRAINT ALL
ALTER TABLE Test2 WITH CHECK CHECK CONSTRAINT ALL