Answer by edosoft for SQL Server 2005 drop column with constraints

This query finds default constraints for a given table. It aint pretty, I agree:

select     col.name,     col.column_id,     col.default_object_id,     OBJECTPROPERTY(col.default_object_id, N'IsDefaultCnst') as is_defcnst,     dobj.name as def_namefrom sys.columns col     left outer join sys.objects dobj         on dobj.object_id = col.default_object_id and dobj.type = 'D'where col.object_id = object_id(N'dbo.test') and dobj.name is not null

[EDIT] Updated per Julien N's comment