Custom Types via TryFrom, TryInto

[SZenglein]

New type enables usage of basic wrapper types and JSON support.

However, there are some cases where database columns can be better represented by structs. In addition, (de-)serializing using structs has the advantage of being able to fail early. A good example is the FromJsonQueryResult derive, where I can kind of shift the deserialization error to sea-orm.

I think it might be best explained using serde:

The DeriveValueType macro behaves the same as #[serde(transparent)] ,

Serde also has try_from. Sea-orm could first read as the respective database type and then use try_from to fallibly convert to the target type. The same applies in the reverse direction.

This can be implemented manually already, but requires 4 traits as specified in the docs, which is a lot of boilerplate.