Re: mogrify and indent features for jsonb

On 15 February 2015 at 03:06, Andrew Dunstan <andrew(at)dunslane(dot)net> wrote:

>
> Attached is a patch to provide a number of very useful facilities to jsonb
> that people have asked for. These are based on work by Dmitry Dolgov in his
> jsonbx extension, but I take responsibility for any bugs.
>
> The facilities are:
>
> new operations:
>
> concatenation: jsonb || jsonb -> jsonb
> deletion: jsonb - text -> jsonb
> deletion: jsonb - int -> text
>
> new functions:
>
> produce indented text: jsonb_indent(jsonb) -> text
> change an element at a path: jsonb_replace(jsonb, text[], jsonb) -> jsonb.
>
>
> It would be relatively trivial to add:
>
> delete an element at a path: jsonb_delete(jsonb, text[]) -> json
>

Would this support deleting "type" and the value 'dd' from the following?:

{"a": 1, "b": 2, "c": {"type": "json", "stuff": "test"}, "d":
["aa","bb","cc","dd"]}

>
> and I think we should do that for the sake of completeness.
>
> The docs might need a little extra work, and the indent code definitely
> needs work, which I hope to complete in the next day or two, but I wanted
> to put a stake in the ground.
>

This is high on my wanted list, so thanks for working on this.

Seems to work well for me with a few tests.

Is there a way to take the json:

'{"a": 1, "b": 2, "c": {"type": "json", "stuff": "test"}, "d":
["aa","bb","cc","dd"]}'

and add "ee" to "d" without replacing it? I can think of ways of currently
doing it, but it's very convoluted just for pushing a value to an array.

Also, are there any plans to support the following?:

jsonb - text[] # Provide list of keys to delete in array
jsonb - jsonb # Deduplicate key:value pairs
jsonb && jsonb # Return overlapping jsonb (opposite of jsonb - jsonb)

Thanks

Thom