Re: [Haskelldb-users] HaskellDB and joins

[Bjorn B. <bri...@cs...>]

On Jul 28, 2006, at 11:45 AM, Daniel Larsson wrote:

> I started looking at HaskellDB recently, and it's quite =20
> interesting. One
> thing I would like to do, which I can't find any support for, is outer
> joins. Is this something that is planned to support, or have I missed
> something?

You are perfectly right that outer join support is missing. It's the =20
query language feature that I miss the most, and I would like to =20
implement it. The problem is that it seems a bit difficult to figure =20
out how to do it in the current version of HaskellDB, since with an =20
outer join, the fields form the second table can be NULL, even if =20
they are not nullable. This is one of the reasons why I believe that =20
HaskellDB could benefit from moving to a non-monadic query language =20
closer to that of CoddFish [1].

/Bj=F6rn

[1] http://lmf.di.uminho.pt/wiki/bin/view/PURe/CoddFish