Here you want to use the "describe" command in Postgresql. Assuming that you want to get information about a database table named users, and you're logged into a Postgresql database using the psql client, issue this command at the psql prompt:

\d users

This will provide a description of the table named users. Your output from this command should look like this:

mydatabase=> \d users

                             Table "public.users"
    Column    |          Type          |              Modifiers
--------------+------------------------+------------------------------------
 user_id      | integer                | not null default 
                                         nextval('"users_user_id_seq"'::text)
 username     | character varying(24)  | not null
 firstname    | character varying(24)  | not null
 lastname     | character varying(24)  | not null
 companyname  | character varying(24)  |
 password     | character varying(255) | not null
 email_addr   | character varying(24)  | not null
Indexes:
    "users_pkey" PRIMARY KEY, btree (user_id)

Of course the fields in your database will be different, but the output should appear similar.

This output was generated with the psql client for Postgresql 8.0.3.