On 03/14/2018 10:02 AM, Alexander Farber wrote:
> Thank you, Ivan! I am trying to apply your suggestion to my table -
>
> On Wed, Mar 14, 2018 at 5:34 PM, Ivan E. Panchenko
> <i.panchenko@postgrespro.ru <mailto:i.panchenko@postgrespro.ru>> wrote:
>
> Hi Alex,
>
> SELECT string_agg(x->>'letter','') FROM json_array_elements(
>
> '[{"col": 7, "row": 12, "value": 3, "letter": "A"}, {"col": 8,
> "row": 12, "value": 10, "letter": "B"}, {"col": 9, "row": 12,
> "value": 1, "letter": "C"}, {"col": 10, "row": 12, "value": 2,
> "letter": "D"}]'::json
>
> ) x;
>
>
> # select * from words_moves where gid=656 order by played desc limit 3;
> mid | action | gid | uid | played
> |
> tiles | score
>
------+--------+-----+------+-------------------------------+------------------------------------------------------------------------------------------------------+-------
> 1353 | swap | 656 | 7 | 2018-03-14 17:22:18.430082+01 |
> "ЙНРР"
> | ¤
> 1352 | play | 656 | 1199 | 2018-03-14 16:55:45.898379+01 | [{"col":
> 4, "row": 7, "value": 2, "letter": "С"}, {"col": 5, "row": 7, "value":
> 3, "letter": "У"}] | 19
> 1351 | play | 656 | 7 | 2018-03-14 16:38:48.132546+01 | [{"col":
> 9, "row": 11, "value": 5, "letter": "Ж"}, {"col": 9, "row": 13, "value":
> 2, "letter": "М"}] | 16
> (3 rows)
>
> by trying the following:
>
> # select string_agg(x->>'letter', ' ') from (select
> jsonb_array_elements(tiles) from words_moves where gid=656 and
> action='play' order by played desc limit 5) x;
> ERROR: 42883: operator does not exist: record ->> unknown
> LINE 1: select string_agg(x->>'letter', ' ') from (select jsonb_arra...
> ^
> HINT: No operator matches the given name and argument type(s). You
> might need to add explicit type casts.
> LOCATION: op_error, parse_oper.c:728
>
> I am probably missing something obvious?
Do you still have non-arrays in the tile field?:
https://www.postgresql.org/message-id/CAADeyWgYKKaArJb6JK_xEtSO%3D7aeNaYqBu_ef-D5W7s8EFPfpQ%40mail.gmail.com
>
> Regards
> Alex
>
>
--
Adrian Klaver
adrian.klaver@aklaver.com
