Re: Proposal for JSONB functions for internal representation casting insted text-casting

2016-01-06 19:52 GMT+01:00 Robert Haas <robertmhaas(at)gmail(dot)com>:

> On Sun, Jan 3, 2016 at 3:24 PM, Peter Krauss <ppkrauss(at)gmail(dot)com> wrote:
> > The usefulness of ->> operator is indisputable, but even with boolean
> or
> > numeric values, with good binary internal representation, it returns
> JSONB
> > value as text data type.
> >
> > The simple (myJSONB->>'myField')::expectedType is not enough because:
> >
> > 1) there are no internal optimization, need two-step casting, first
> > bynary-to-text, them text-to-expectedType.
> >
> > 2) if expectedType is not the expected (in the associated jsonb_typeof),
> > generates an error... The ideal "return NULL" convention is not easy to
> > implement with usual casting.
>

@2 looks little bit dangerous. If expected number isn't number, but a
text, then I'll expect a exception in all cases.

Pavel

>
> Agreed, something like this would be useful.
>

>
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> Robert Haas
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