Adding an IDENTITY column to a source table

To create an IDENTITY column in a table named composers, define the table as follows:

create table composers (
    id          numeric(m,n)     identity,
    comp_fname  char(30)         not null,
    comp_lname  char(30)         not null,
    text_col    text
)

where m =< 38 and n always = 0.

To add an IDENTITY column to an existing table, enter:

alter table table_name add id numeric(10,0) identity