json/jsonb functions and operators

[gkaracha]

Hello! I am migrating some queries to Rel8, and I find myself in need of operators that deal with jsonb data. In particular #>> (or -> and ->> would also do) and jsonb_array_elements. I haven't found anything about them in the Rel8 documentation. Are they supported at the moment in any form? Cheers!

[sfwc]

I don't think there's built-in support for this as of 1.4.1, maybe it's been added more recently? But there's always binaryOperator, e.g.

objectLookup :: Expr (JSONBEncoded Aeson.Value) -> Expr Text -> Expr (Maybe Text)
objectLookup = binaryOperator "->>"   

[gkaracha]

Thanks! Yeah, I did manage to get the basic binary operators using binaryOperator indeed, but jsonb_array_elements is still giving me grief. It's impossible to ascribe it a proper type, currently, but it seems there has been progress on that front:

rel8/src/Rel8/Query/Function.hs

Line 25 in 77fb0a3

-- | Select each row from a function that returns a relation. This is

Hopefully it will be possible to do so with the next release

[gkaracha]

Indeed with the latest release one can simply do the following so I think we can close this :)

arrayElements :: Expr (Maybe Value) -> Query (Expr Value)
arrayElements = queryFunction "jsonb_array_elements"