SQL中ntext、text數據替換

ColName是ntext格式，裏面放一些html代碼，我想把中間的段落標記<p>和</p>清除

 

update TestTable set ColName=replace(cast(ColName as varchar(8000)),'<p>','')

update TestTable set ColName=replace(cast(ColName as varchar(8000)),'</p>','')