Add DEFAULT constraint with a generated name

Question

In SQL Server I have an existing table. Now I want to add a DEFAULT constraint to one of the columns - without having to define a name for it.

-- generated name works fine when creating new column
ALTER TABLE [xyz]
ADD [newColumn] int NOT NULL DEFAULT 0

-- when adding a default value afterwards I seem to have to provide a name
ALTER TABLE [xyz]
ADD CONSTRAINT [iDontWantToPutANameHere] DEFAULT 0 FOR [existingColumn]

Answer 1

You can create default constraint for an existing column, without specifying its name, e.g.:

create table test
(
    existing_column int
)

alter table test
    add default 0 for existing_column

However, there are plenty articles, suggesting that it is better to name constraints explicitly. Because of it is harder to drop or other way alter system-named constraint. Also if you have multiple instances of the same database, the default name will no be the same across them.