sql - alternatives to REPLACE on a text or ntext datatype

Question

I need to update/replace the data in datatable.column. The table has a field named Content. I'm using the REPLACE function. Since the column datatype is NTEXT, SQL Server doesn't allow me to use the REPLACE function.

I can't change the datatype because this database is 3rd party software table. Changing the datatype will cause the application to fail.

UPDATE [CMS_DB_test].[dbo].[cms_HtmlText] 
SET Content = REPLACE(Content,'ABC','DEF') 
WHERE Content LIKE '%ABC%' 

I Receive this error:

Msg 8116, Level 16, State 1, Line 1 Argument data type ntext is invalid for argument 1 of replace function.

• Can I fix this with T-SQL? Does someone have an example how to read and to loop?
• Since this is onetime conversion, maybe I can change to another type but I'm afraid I'm messing up the data.

There is a primary key field: name: ID - integer - it's an identity.... So I need to think about this too. Maybe set the Identity to N temporary.

Please advise on how to achieve the REPLACE function?

Approx. 3000 statements need to be updated with a new solution.

Answer 1

IF your data won't overflow 4000 characters AND you're on SQL Server 2000 or compatibility level of 8 or SQL Server 2000:

UPDATE [CMS_DB_test].[dbo].[cms_HtmlText] 
SET Content = CAST(REPLACE(CAST(Content as NVarchar(4000)),'ABC','DEF') AS NText)
WHERE Content LIKE '%ABC%' 

For SQL Server 2005+:

UPDATE [CMS_DB_test].[dbo].[cms_HtmlText] 
SET Content = CAST(REPLACE(CAST(Content as NVarchar(MAX)),'ABC','DEF') AS NText)
WHERE Content LIKE '%ABC%'