While I develop the application's GUI I use the database from the command line (psql). While some queries are self-contained others need user input. I've not found a search term that locates this information in the postgres-12 user manual and my web searches suggest that using '&' should work.
I tried the latter with this query but postgres didn't like it. (There may well be other errors in it so don't hesitate to point out my mistakes.)
------ /* This query selects all activity information for a named person */
/* Specify columns */ SELECT p.lname, p.fname, p.loc_nbr, p.job_title, p.direct_phone, p.active, o.org_name, l.loc_nbr, l.loc_name, a.act_date, a.act_type, a.notes, a.next_contact /* Specify tables. */ FROM People AS p JOIN Organizations AS o ON o.org_nbr = p.org_nbr JOIN Locations AS l ON l.org_nbr = o.org_nbr and l.loc_nbr = p.loc_nbr JOIN Activities AS a ON a.person_nbr = p.person_nbr /* Specify rows */ WHERE p.lname = &p.lname AND p.fname = &p.fname; -----
Suggestions on what I should read to learn more about this subject are appreciated.