Re: [SQL] Better way to sort a JSONB array?
| От | Michael Moore |
|---|---|
| Тема | Re: [SQL] Better way to sort a JSONB array? |
| Дата | |
| Msg-id | CACpWLjM3tD-n3tqMZeyTjKTSG_EeBC_t9mFq8PRtbybYyzXK2g@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: [SQL] Better way to sort a JSONB array? ("David G. Johnston" <david.g.johnston@gmail.com>) |
| Ответы |
Re: [SQL] Better way to sort a JSONB array?
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| Список | pgsql-sql |
Hi David,
Maybe there isn't a less verbose way. It just seems like a bit much that I have to take the jsonb array, convert it into a relation so that SELECT can operate on it, only so that I can sort it, and then convert it back into a jsonb array object. I was hoping for something like json_table2.aggSort("portal_name"). I'm not actually using json_table2 as a name, that was just for my minimalist example. As mentioned, my real project consists of refactoring a pgsql function which uses TEMP tables to NOT use temp tables, but instead, JSONB objects.
Thanks !
Mike
On Mon, Aug 7, 2017 at 2:36 PM, David G. Johnston <david.g.johnston@gmail.com> wrote:
This works, but surely there is a better way to do it:What do you mean by "better"?select jsonb_agg(row_to_json(alias)) from(Select * from jsonb_populate_recordset(null::tx_portal, json_table2) order by portal_name) alias into json_table2;It sorts the json_table2 array in "portal_name" order.The only other possibility would be:CREATE TABLE json_table2 ASselect jsonb_agg(row_to_json(alias) order by portal_name) from(select * from jsonb_populate_recordset(...)) alias;i.e., move the order by into the aggregate; I prefer CREATE TABLE AS over SELECT INTO ...I don't know why you are thinking there is a better way...you are doing two distinct actions here and you have two invocations of select...seems like the minimal possible number of sub-statements to me. No one has written a c-language function for core that provides a more friendly interface to this. Looking at your query doing so using dynamic SQL within a pl/pgsql function would seem reasonably easy.I would suggest not using "json_table2" as both the name of the input variable and the target table name - it can be confusing to follow when you overload names like that.David J.
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