how to select one column into another in same table?

Currently I can select one column into another with two statements:

alter table <table_name> add column id_old int;
update <table_name> set id_old = id;

Is there a way to do this in one statement with a select into? I have
tried various select statements but want the new column (with the same
data) to be in the same table and to have it execute much more quickly
that the two statements currently do.

thanks

J.V.