Advanced DB mapping¶
- [HRR is DB agnostic, meaning that user defined types or extensions are not supported, by choice of HRRs authors.
- This chapter should give an overview how to approach that topic]
[This chapter includes a view on how HRR interoperates with postgres additions to the SQL standard]
date/time types¶
[how are date/time values mapped by HRR? is there any special way necessary to deal with them?]
JSON(B) type¶
- [Show how a patched HRR library can derive JSON(B) as ByteString but provides
- no abstraction for it in its query syntax (like cf. https://www.postgresql.org/docs/9.5/static/functions-json.html)]
Enums¶
- [Show how with some TH magic you can use HRRs data type derivation to actually
- generate Haskell sum types and HRR projections from postgres enums, so that this feature becomes usable quite well]
Arrays¶
- [There are yet some experiments to do here on how to best deal with
postgres arrays, e.g. parse the literals into Haskell lists with custom FromSql / ToSql instances - in short, proof of concept still missing]
- [Is it possible to use a type alias on the DB and generate a mapping to a Haskell
- newtype, for additional type safety?]