To remove a default from the database entirely, use the drop default command. Unbind the default from all columns and user datatypes before you drop it. (See “Unbinding defaults”.) If you try to drop a default that is still bound, Adaptive Server displays an error message and the drop default command fails.
Here is how to remove citydflt. First, you unbind it:
sp_unbindefault citydft
Then you can drop citydft:
drop default citydflt
The complete syntax of drop default is:
drop default [owner.]default_name [, [owner.]default_name] ...
A default can be dropped only by its owner. See the Reference Manual: Procedures and the Reference Manual: Commands.