Store enum as jsonb?

[spiffytech]

I have some data shaped like this:

enum MyEnum {
  Foo(i16)
  Bar(i16)
}

struct MyTable {
  ...
  my_enum: Option<MyEnum>
}

With a Postgres schema like this:

create table my_table (... my_enum: jsonb);

What do I need to do allow sqlx to read from the database using query_as!(MyTable, ...), and write a row to the database?

(I'm trying to store as jsonb because sqlx doesn't support this data type directly, and storing arbitrary data structures as jsonb column seems like a reasonable workaround. I also have more complicated data types I'll want to treat the same way.)

If I try derive macros, or try setting the MyTable field to type `Option<sqlx::types::Json>, I get errors saying enums are unsupported.

I tried to manually impl Encode/Decode/Type, but writes error out with error returned from database: unsupported jsonb version number 123. I'm not sure if that's related to storing an Option<MyEnum> instead of a MyEnum. I also don't know if there's an easier way to handle this.

impl sqlx::Type<Postgres> for MyEnum {
    fn type_info() -> PgTypeInfo {
        PgTypeInfo::with_name("jsonb")
    }
}
impl<'q> sqlx::Encode<'q, Postgres> for MyEnum {
    fn encode_by_ref(&self, buf: &mut PgArgumentBuffer) -> sqlx::encode::IsNull {
        let json = serde_json::to_string(&self).unwrap();
        <&str as sqlx::Encode<Postgres>>::encode(&json, buf);
        sqlx::encode::IsNull::No
    }
}
impl<'r> sqlx::Decode<'r, Postgres> for MyENum {
    fn decode(value: PgValueRef<'r>) -> Result<Self, sqlx::error::BoxDynError> {
        let json_str = value.as_str()?;
        let my_enum: MyEnum = serde_json::from_str(json_str)?;
        Ok(my_enum)
    }
}