You cannot alter one table using Visual Database Tools (VDT) unless you are either a member of db_dbowner or sysadmin

Members of db_ddladmin fixed database role or users who have explicitly been granted CREATE TABLE permissions cannot alter the table using VDT.

If you are connected to an instance of Yukon with a login whose mapped user in a given database is either a member of the db_ddladmin or has been explicitly granted ALTER TABLE permissions, you cannot change anything in the table Design grid, from within Visual Database Tools.

The code implemented in vdt80.dll user rights on a table permits "ALTERing" the design of any table object when it’s from an instance of SQL Server previous to SQL Server 2005, while if it’s SQL Server 2005 or higher, it will not permit such operation.

This is a known issue for which there is no planned fix for the moment. So either make your db_ddladmin users members of db_dbowner fixed database role or ask them to transform their DDL wishes into TSQL form so that they can avoid using the graphical tools.

Hope that at least being aware of the existence of this problem might help anyone.

See you in my next post!