This blog defines how to update default value of column in SQL Server.
--How to update Default Value of column in SQl Server
--Suppose I have added Column 'Status' in Employee Table
--And I want to give a default value so Normally we do as following:
--alter table Employee add default 'Active' for Status
--Note: The disadvantage of doing this is, we will be unable to change our Default value of Status in Future.
--If I am doing like this:
--alter table employee add constraint [default_Constraint_status] default 'Active' for status
--So when you want to update /change your default in status column so do following action:
--First drop you constraint Name
--eg. alter table employee drop constraint [default_Constraint_status]
--And then write
--alter table employee add constraint [default_Constraint_status] default 'Inactive' for status