extract enum fields to named structs

[cmoog]

Addresses #311

Maybe it's appropriate to continue this refactor for Expr as well as the remaining Statement variants? Those seem much less pressing though since nearly all have <= 3 fields.

[alamb]

This seems like a useful improvement to me (though as @cmoog points out a fairly large backwards incompatible change which will cause pain for downstream crates)

Any other thoughts?

cc @Dandandan and @andygrove

[Dandandan]

Addresses #311

Maybe it's appropriate to continue this refactor for Expr as well as the remaining Statement variants? Those seem much less pressing though since nearly all have <= 3 fields.

Thank you for this PR.

I think it make sense if we do this, consistently do it for all statement variants.

I would be OK to not do the same thing for Expr now, I am not sure if there is a similar need to do it there too?

[alamb]

Closing old seemingly stalled PR. Please re-open if this was a mistake

[AugustoFKL]

@alamb @Dandandan I currently would love to have that approach, since my usage is requiring a lot of "unreachable!()" because of that.

Is that idea still OK? I can work on that this week

[alamb]

Hi @AugustoFKL -- I think given that the sqlparser API is basically stable, I don't really want to contemplate such a large change at this time :(