Default Field Value at Table Creation Time

Syntax:

[FieldName] type CONSTRAINT [constraint_name] DEFAULT default_value

Example:

CREATE TABLE [Clients]

(

    ClientID  bigint   NOT NULL IDENTITY(1,1) CONSTRAINT [PK_Clients] PRIMARY KEY,

    CreatedOn datetime NOT NULL CONSTRAINT [DF_Clients_CreatedOnUtc] DEFAULT GETDATE()

    ...

)

And for an already created table:

ALTER TABLE Clients

ADD CONSTRAINT [DF_Clients_CreatedOn] DEFAULT GETDATE() FOR CreatedOn