Alias to a join query - sql

Question

( SELECT Vraboteni.v, Ulogi.p, Zarabotuva.honorar
FROM Vraboteni, Ulogi, Zarabotuva
WHERE Vraboteni.v = Ulogi.v
AND ima_uloga='sporedna'
AND Ulogi.p = Zarabotuva.p
) as F
JOIN
( SELECT Vraboteni.v, Ulogi.p, Zarabotuva.honorar
FROM Vraboteni, Ulogi, Zarabotuva
WHERE Vraboteni.v = Ulogi.v
AND ima_uloga='glavna'
AND Ulogi.p = Zarabotuva.p
) as S
ON (F.honorar > S.honorar)
Can anyone tell me what is wrong with the syntax that I am using above? I'm having the same issue over multiple queries and I'm not sure I quite understand how I am supposed to assign an alias when I use a join (having the same issue when trying to assign alliases to multiple nested joins)

Answer 1

The subselects you join should be considered as a normal table or view, so imagine they are, and your select statement looks like this:
SELECT1 as F
JOIN SELECT2 as S ON (F.honorar > S.honorar)
This statement is missing essential parts, like a SELECT and FROM clause.
So fix it, if you want to join two selects, you should encapsulate them in another select, so you get:
SELECT
S.*,
F.*
FROM
(SELECT ... ) AS F
JOIN (SELECT ...) AS S ON (F.honorar > S.honorar)
Alternatively, you could get rid of the two subselects, use normal joins for all your tables, and end up with a query like this:
SELECT
Vraboteni.v, Ulogi.p, Zarabotuva.honorar
FROM
Vraboteni AS v1
JOIN Ulogi AS u1 ON v1.v = u1.v
JOIN Zarabotuva AS z1 ON u1.p = z1.p
CROSS JOIN Vraboteni AS v2 -- Not sure if you would want/need a condition here
JOIN Ulogi AS u2 ON v2.v = u2.v
JOIN Zarabotuva AS z2 ON u2.p = z2.p
WHERE
v1.ima_uloga = 'sporedna' -- Not sure if this should be v1, u1 or z1
AND v2.ima_uloga = 'glavna'
AND z1.honorar > z2.honorar

Answer 2

this is what you need to do:
SELECT *
FROM
(SELECT Vraboteni.v
, Ulogi.p
, Zarabotuva.honorar
FROM Vraboteni
, Ulogi
, Zarabotuva
WHERE Vraboteni.v = Ulogi.v
AND ima_uloga = 'sporedna'
AND Ulogi.p = Zarabotuva.p) AS F
JOIN
(SELECT Vraboteni.v
, Ulogi.p
, Zarabotuva.honorar
FROM Vraboteni
, Ulogi
, Zarabotuva
WHERE Vraboteni.v = Ulogi.v
AND ima_uloga = 'glavna'
AND Ulogi.p = Zarabotuva.p) AS S ON F.honorar > S.honorar;