Re: Extract numeric filed in JSONB more effectively - Mailing list pgsql-hackers

From Andy Fan
Subject Re: Extract numeric filed in JSONB more effectively
Date
Msg-id CAKU4AWpoX9aNosepmz_y9gJhkWo0O=0HEtpThxJQiS16LHWWBw@mail.gmail.com
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In response to Re: Extract numeric filed in JSONB more effectively  (Matthias van de Meent <boekewurm+postgres@gmail.com>)
Responses Re: Extract numeric filed in JSONB more effectively
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On Tue, Aug 1, 2023 at 7:03 PM Matthias van de Meent <boekewurm+postgres@gmail.com> wrote:
On Tue, 1 Aug 2023 at 06:39, Andy Fan <zhihui.fan1213@gmail.com> wrote:
>
> Hi:
>
> Currently if we want to extract a numeric field in jsonb, we need to use
> the following expression:  cast (a->>'a' as numeric). It will turn a numeric
> to text first and then turn the text to numeric again.

Why wouldn't you use cast(a->'a' as numeric), or ((a->'a')::numeric)?

Thanks for this information! I didn't realize we have this function
already at [1].


--
Best Regards
Andy Fan

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