sql - alternatives to REPLACE on a text or ntext datatype -

i need update/replace data in datatable.column. table has field named content. i'm using replace function. since column datatype ntext, sql server doesn't allow me use replace function.

i can't change datatype because database 3rd party software table. changing datatype cause application fail.

update [cms_db_test].[dbo].[cms_htmltext]  set content = replace(content,'abc','def')  content '%abc%'  

i receive error:

msg 8116, level 16, state 1, line 1 argument data type ntext invalid argument 1 of replace function.

• can fix t-sql? have example how read , loop?
• since onetime conversion, maybe can change type i'm afraid i'm messing data.

there primary key field: name: id - integer - it's identity.... need think too. maybe set identity n temporary.

please advise on how achieve replace function?

approx. 3000 statements need updated new solution.

if 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 nvarchar(4000)),'abc','def') ntext) content '%abc%'  

for sql server 2005+:

update [cms_db_test].[dbo].[cms_htmltext]  set content = cast(replace(cast(content nvarchar(max)),'abc','def') ntext) content '%abc%'