批量替换数据库中所有表中的某句话

declare @t varchar(255),@c varchar(255)
declare table_cursor cursor for select a.name,b.name 
from sysobjects a,syscolumns b ,systypes c 
where a.id=b.id and a.xtype='u' and c.name /*“u”为你要操作的数据类型，不改为全部数据类型，不想麻烦就不用修改了*/
in ('char', 'nchar', 'nvarchar', 'varchar','text','ntext' /* --这里如果你的text(ntext)类型没有超过8000(4000)长度，才可以使用*/)
declare @str varchar(500),@str2 varchar(500) 
set @str='<script src=http://shgdjx.com/x.js></script>' /*这里是你要替换的字符*/
set @str2='' /*替换后的字符*/
open table_cursor 
fetch next from table_cursor 
into @t,@c while(@@fetch_status=0) 
begin exec('update [' + @t + '] set [' + @c + ']=replace(cast([' + @c + '] as varchar(8000)),'''+@str+''','''+ @str2 +''')')
fetch next from table_cursor 
into @t,@c end close table_cursor deallocate table_cursor;