Postgres reference SELECTed aliases in ORDER BY/GROUP BY clauses, but _not_ in HAVING: test=# create table event (who text not null, test(#

Postgres reference SELECTed aliases in ORDER BY/GROUP BY clauses, but _not_ in HAVING: test=# create table event (who text not null, test(# what text not null, test(# at timestamptz not null default now()); CREATE TABLE test=# insert into event (who, what) test-# values ('Bob', 'sent a message'), test-# ('Alice', 'received a message'), test-# ('Alice', 'sent a message receipt'), test-# ('Bob', 'received the message receipt'), test-# ('Bob', 'waited patiently for a response'), test-# ('Bob', 'worried whether his message had been well-received'), test-# ('Bob', 'paced'), test-# ('Alice', 'forgot to reply for two weeks'), test-# ('Bob', 'began to panic'), test-# ('Bob', 'fled the country for Moldova in a fit of panic'), test-# ('Alice', 'finally remembered to reply'), test-# ('Bob', 'never got it'); INSERT 0 12 test=# select who as "The poor sod", test-# count(what) as "Events" test-# from event test-# group by "The poor sod" test-# order by "Events" desc; The poor sod | Events --------------+-------- Bob | 8 Alice | 4 (2 rows)