Re: Turn a json column into a table

On Sat, 19 Feb 2022 at 23:22, Shaozhong SHI <shishaozhong(at)gmail(dot)com> wrote:

>
>
> On Sat, 19 Feb 2022 at 22:47, Rob Sargent <robjsargent(at)gmail(dot)com> wrote:
>
>> On 2/19/22 15:40, Shaozhong SHI wrote:
>>
>>
>>
>> On Tue, 15 Feb 2022 at 08:37, Karsten Hilbert <Karsten(dot)Hilbert(at)gmx(dot)net>
>> wrote:
>>
>>> Hi Ion,
>>>
>>> > there seems to be an example in the archives
>>> >
>>> https://www.postgresql.org/message-id/20180526150323.GB28324%40momjian.us
>>>
>>> Many thanks ! I shall indeed go Read The Fine Manual now.
>>>
>>> In case I might have further questions I would like to come back,
>>> post my work and understanding, and ask for specific guidance on
>>> the aspects I can't fully solve myself.
>>>
>>> Thanks again,
>>> Karsten
>>>
>>>
>> In the JSON column, one key can be seen present as other keys. But, when
>> use json_object_keys, it did not turn up at all.
>>
>> Is there a way to cast json column as text, and extract values from text?
>>
>>
>> Nothing in https://www.postgresql.org/docs/14/functions-json.html helps?
>>
>
> That is very odd. That key and vale disappeared when the column casted as
> text.
>
> Regards,
>
> David
>

That is a very odd challenge. That key and value do appear in the data set
but it will disappear whenever you do something with the json column.

Regards,

David