创建触发器时添加运算符的问题

Question

请参阅下面的代码以及错误消息。

CREATE TRIGGER SubscriptionDescriptionNotes

ON [dbo].[Subscriptions]

AFTER INSERT, UPDATE

AS

UPDATE dbo.Subscriptions

SET [Description] = -- parse Parameter column and add to Description

                             [Parameters]  + Description

FROM [dbo].[Subscriptions] s

  WHERE s.[Parameters] LIKE '' --again parse parameter with condition what you want

  

Msg 402，Level 16，State 1，Procedure SubscriptionDescriptionNotes，Line 13   数据类型ntext和nvarchar在add运算符中不兼容。