千年老妖

1.select array_to_json('{{1,5},{99,100}}'::int[])2.select row_to_json(row(1,'foo'))3.select to_json('Fred said "Hi"'::text)4.select json_array_length('[1,2,3,{"f1":1,"f2":[5,6]},4]')5.select * from json_each('{"a":"foo& Read More