"Jie Liang" <jie@stbernard.com> writes:
> You will see AAA associate with 'whatever', it's an internal variable,
> but how could I use it in my SQL query?
regression=# \set AAA 'whatever'
regression=# select :AAA;
ERROR: column "whatever" does not exist
regression=# \set AAA '\'whatever\''
regression=# select :AAA;
?column?
----------
whatever
(1 row)
regards, tom lane