I don't understand, why the following query produced an error. Whereas in other dbms (eg mysql) this sort of query is absolutely legal.
ERROR: Syntax error at the end of input
LINE 1: SELECT * FROM "addr_country" AS c JOIN "addr_state" AS s
^
SQL state: 42601
Character: 59
Adding an on-clause to the query makes it working:
SELECT * FROM "addr_country" AS c JOIN "addr_state" AS s
ON c."id" = s."country" AND s.id = 10