How to delete an existing column with Not Null constraint in SQL Server

Question

I am using SQL Server Management Studio. I have a table Employee . I want to delete the Starting Date and Ending Date columns. Initially, Not Null constraints were assigned to them. Then I changed to Null .

But whenever I am trying to delete these two columns, I am getting an error. Please see the screenshot and help me execute the task.

Thanks in advance

Answer 1

First, drop the constraints.

ALTER TABLE [dbo].[Employee] DROP CONSTRAINT NameYourConstraint;

If you don't now the names:

SELECT *
FROM [sys].[default_constraints]
WHERE [parent_object_id] = OBJECT_ID('[dbo].[Employee]');

Answer 2

You can try removing the contrainsts first -

ALTER TABLE dbo.Employee DROP CONSTRAINT DF__Employee__Starti__47DBAE45;
ALTER TABLE dbo.Employee DROP CONSTRAINT DF__Employee__Ending__5AEE82B9;
ALTER TABLE dbo.Employee DROP COLUMN StartingDate;
ALTER TABLE dbo.Employee DROP COLUMN EndingDate;