Re: ERROR: type "myrowtype" does not exist

On 10/26/18 4:54 AM, Arup Rakshit wrote:
> I was reading the json_populate_record function from the official doc
> https://www.postgresql.org/docs/10/static/functions-json.html#FUNCTIONS-JSON-PROCESSING-TABLE.
> The doc mentioned examples are giving me errors
>
> psql (11.0, server 10.5)
> Type "help" for help.
>
> aruprakshit=# select * from json_populate_record(null::extype,
> '{"x":"foo", "y":43, "q": true}');
> ERROR:  type "extype" does not exist
> LINE 1: select * from json_populate_record(null::extype, '{"x":"foo"...
>                                                  ^
> aruprakshit=# select * from json_populate_record(null::myrowtype, '{"a":
> 1, "b": ["2", "a b"], "c": {"d": 4, "e": "a b c"}}');
> ERROR:  type "myrowtype" does not exist
> LINE 1: select * from json_populate_record(null::myrowtype, '{"a": 1…
>
> What does null::extype, null::myrowtype mean here ?

See this thread:

https://www.postgresql.org/message-id/2a8ae0b7-1fd4-869a-a25e-d598968898c9%40aklaver.com

In meantime:

CREATE TABLE public.test_table (
id integer,
username character varying,
fullname character varying
);

test=> \d test_table
Table "public.test_table"
Column | Type | Collation | Nullable | Default
----------+-------------------+-----------+----------+---------
id | integer | | |
username | character varying | | |
fullname | character varying | | |

test=> select * from json_populate_record(null::test_table, '{"id": 1,
"username": "adrian", "fullname": "adrian klaver"}')
;
id | username | fullname
----+----------+---------------
1 | adrian | adrian klaver
(1 row)

So myrowtype is just a placeholder in the docs for a rowtype that you
need to supply.

>
>
> Thanks,
>
> Arup Rakshit
> ar(at)zeit(dot)io <mailto:ar(at)zeit(dot)io>
>
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com