Question

I have a column with a ‘DEFAULT’ constraint. I’d like to create a script that drops that column.

The problem is that it returns this error:

Msg 5074, Level 16, State 1, Line 1   The object 'DF__PeriodSce__IsClo__4BCC3ABA' is dependent on column 'IsClosed'.  Msg 4922, Level 16, State 9, Line 1  ALTER TABLE DROP COLUMN IsClosed failed because one or more objects access this column. 

I couldn’t find an easy way to drop a column and all its associated constraints (only found big scripts that look into the system table… there MUST (!!) be a ‘nice’ way to do it.)

And as the DEFAULT constraint’s name has been randomly generated, I can’t drop it by name.

---

Update :
The constraint type is ‘DEFAULT’.

I saw the solutions that you all proposed but I find them all really ‘dirty’… Don’t you think? I don’t know if it’s with Oracle or MySQL but it’s possible to do something like:

DROP COLUMN xxx CASCADE CONSTRAINTS  

And it drops all related constraints… Or at least it automatically drops the constraints mapped to that column (at least CHECK constraints!)

Is there nothing like that in MSSQL?

Answer 1

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_name from 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