Modify Table -> modify Default is not working

Hi

I'm using DataGrip for SQL Server

1. Consider I want to modify default value of some column of some table that already has a default value. But it is impossible because on attempt to do so I'll get an error saying "Column already has a DEFAULT bound to it". Com'on! I know that it has a default value! Because I have just changed it!

2. Consider I want to remove default values of some column of some table. In this case I'll remove what was in the default value box. But generated SQL is not even valid!

ALTER TABLE [ddb].dbo.TTable ADD CONSTRAINT TTable_ccolumn_default FOR ccolumn

On attempt to execute it error `Incorrect syntax near the keyword 'FOR'.` would be returned

Am I doing something wrong? Or it is impossible in DataGrip to modify default value of columns?

And if I need to write the SQL to remove the constrains by my own - can DataGrip at list help me to get the names of that constrains?