Trigger for text or Ntext or image data type in SQL Server:

--Main table--
CREATE TABLE [dbo].[Employee_Test]
(
[Emp_ID] [int] IDENTITY(1,1) NOT NULL,
[Emp_name] [text] NULL,
[Emp_Sal] [int] NULL,
[Address1] [varchar](100) NULL
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
--Trigger table--
CREATE TABLE [dbo].[Emp_trigg]
(
[Name] [varchar](max) NULL,
[Old_name] [varchar](max) NULL
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

--Trigger--

ALTER TRIGGER [dbo].[FieldUpdated]

ON [dbo].[Employee_Test]

INSTEAD OF UPDATE

AS

  UPDATE [Employee_Test] SET Emp_name = (SELECT Emp_name FROM Inserted)                     

  WHERE Emp_ID = (SELECT Emp_ID FROM Inserted)                                     

   IF (UPDATE (Emp_name))

  BEGIN

    DECLARE @oldValue nvarchar(max)

    DECLARE @newValue nvarchar(max)

    SET @newValue = (SELECT CONVERT(nvarchar(max), Emp_name) FROM Inserted)

    SET @oldValue = (SELECT CONVERT(nvarchar(max), Emp_name) FROM Deleted)

    IF (@oldValue != @newValue)

    BEGIN

    insert into Emp_trigg(Name,Old_name) values(@newValue,@oldValue)

    END

  END