How to have a custom sort order for a union query in Postgres

Question

With a query like this (simplified for clarity):

SELECT \'East\' AS name, *
FROM events 
WHERE event_timestamp BETWEEN \'2015-06-14 06:15:00\' AND \'2015-06-21 0         


        

Answer 1

I'd add an extra column showing the desired ordering, then use ordinal column positions in the ORDER BY, e.g.

SELECT 1, 'East' AS name, *
...
UNION ALL
SELECT 2, 'West' AS name, *
...
ORDER BY 1

Note that you probably also want UNION ALL since your added columns ensure that every set in the union must be distinct anyway.