joind columns from right table 1 1 2 1 2 1 3 1 2 3 join on expression 2 2 2 2 3 1 2 1 2 2 3 1 2 2 3 3 1 2 2 3 join on and chain 2 3 2 3 2 3 2 3 1 1 3 1 2 2 3 2 4 join on aliases 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 join on complex expression 2 3 2 3 2 3 2 3 2 3 duplicate column names {"a1":1,"tab1_copy.a1":2} {"a1":1,"tab1_copy.a1":2} {"a1":1,"copy.a1":2} {"a1":1,"tab1_copy.a1":2} {"a1":1,"tab1_copy.a1":2} subquery 1 1 1 2 1 2 2 3 1 2 subquery expression 2 1 2 2 3 1 2 2 subquery column alias 1 2 2 3 1 2 2 3 1 2 2 3 subquery alias 1 2 2 3 1 2 2 3 1 2 2 3 1 2 2 3 {"a1":1,"s.a1":2}