How to Remove a NOT NULL Constraint in SQL Server in SQL Server
To remove a
NOT NULL constraint for a column in SQL Server, you use the
ALTER TABLE .... ALTER COLUMN command and restate the column definition.
alter table products alter column brand_id smallint; -- undeclared attributes as NOT NULL will go back to default settings which is null in this case alter table products alter column brand_id smallint null; -- define the NULL attribute over a column