28.11.2017 13:25, Bjorn T Johansen пишет:
On Tue, 28 Nov 2017 11:28:55 +0300
"Ivan E. Panchenko" <i.panche...@postgrespro.ru> wrote:
Hi Bjorn,
28.11.2017 11:18, Bjorn T Johansen пишет:
Hi.
Just starting to look at how to use jsonb columns and I have a question. I have
found out that I can use the following to search for a value
inside the jsonb column:
select * from orders where info ->> 'customer' = 'John Doe' (where info is
the jsonb column)
But what if the jsonb column contains an json array, how can I search then?
info -> [ { "customer" : "John Doe" } ]
If you know the index in array, you can search like
info->0->>'customer'
If you want to search in any array element, you need to use JSQUERY
extension,
see https://github.com/postgrespro/jsquery
btw, using PostgreSQL 9.6 but will be moving to 10 soon.
Regards,
BTJ
Regards,
Ivan
Thx... :)
btw, just managed to use the following sql:
select * from orders where info @> '{"recs": [{ "customer":"John Doe"}]}'
(changed my json string to info -> { "recs: [ { "customer" : "John Doe" } ] }
And this seems to work but is this the "wrong" way of doing it or?
Yes, definitely it works, and is be supported by GIN index.
Nevertheless, I recommend you to have a look at JSQUERY which allows
more complex queries, also with index support.
BTJ
Regards,
Ivan
