title: T-SQL: How to deny update on one column of a table via trigger?
body: <p>Question: <br />
  In our SQL-Server 2005 database, we have a table T_Groups.<br />
  T_Groups has, amongst other things, the fields ID (PK) and Name.</p>
  
  <p>Now some idiot in our company used the name as key in a mapping table...<br />
  Which means now one may not alter a group name, because if one does, the mapping is gone...
  <br />
  Now, until this is resolved, I need to add a restriction to T_Groups, so one can't update the group's name. <br />
  Note that insert should still be possible, and an update that doesn't change the groupname should also be possible.<br /></p>
  
  <p>Also note that the user of the application &amp; the developers have both dbo and sysadmin rights, so REVOKE/DENY won't work.
  <br /><br />
  How can I do this with a trigger ?</p>