>>> Along the lines of the equality operator; I have ran into issues trying
to
>>> pivot a table/result set with a json type due what seemed to be no
>>> equality
>>> operator.
>>
>> For the curious, and also use-case considerations for development, would
>> you
>> be able to share what it is you are doing (and how) that combines full
>> json
>> documents with pivoting?
>>
>> Compound types holding source data for a pivot seems problematic since
>> generally all the pivot components are single-valued and, for data, often
>> numerical.
>would also like to see this. json type has completely displaced
>crosstab in my usage. I don't typically pivot json though: I pivot the
>raw data then transform to json. With limited exceptions I consider
>storing json in actual table rows to be an anti-pattern (but it should
>still work if you do it).
I could not figure out what I was doing last month to reproduce this. So I
did a small pivot poc, and it is erroring on the max function. So it is
probably not the same issue. My guess is I tried the using the GREATEST
function as a hail marry (which would not have worked) and got the following
message; ERROR: could not identify a comparison function for type json and
then thought/hopped it was the same thing when reading the emails.
CREATE TABLE bad_table_json(id int, detail_type text, details json);
INSERT INTO bad_table_json values(1, 'a', '{"a":1}'::json);
INSERT INTO bad_table_json values(1, 'b', '{"a":1}'::json);
INSERT INTO bad_table_json values(1, 'c', '{"a":1}'::json);
SELECT id
,MAX(CASE WHEN detail_type = 'a' THEN details END) AS a
,MAX(CASE WHEN detail_type = 'b' THEN details END) AS b
,MAX(CASE WHEN detail_type = 'c' THEN details END) AS c
FROM bad_table_json
GROUP BY id
--
View this message in context:
http://postgresql.1045698.n5.nabble.com/json-datatype-and-table-bloat-tp5776182p5776947.html
Sent from the PostgreSQL - general mailing list archive at Nabble.com.