Question

I have a PostgreSQL database with two tables named “user” and “group”.
They have different columns, but I want to join them.

user: id, firstname, lastname, email, registrationdate

group: id, name, desc, createdate

I can do two separate queries:
select * from “user” where … order by “registrationdate” asc;
select * from “group” where … order by “createdate” asc;

Is it possible to join these two queries into one and order all by date?
The different columns could be NULL, because they do not have the same column names.

Is this possible?
What I wanna do is a search in which user and groups will be displayed mixed ordered by the date.

Thanks & Best Regards.

Answer 1

This seems all kinda wrong but you can try

SELECT u.id, u.firstname || ' ' || u.lastname || ' ' || u.email, u.registrationdate AS DateVal
FROM user u
UNION ALL
SELECT g.id, g.name || ' ' || g.desc, g.createdate
FROM group g
ORDER BY 3