Re: [Haskelldb-users] Request for code review: Patch removing "distinct" option, adds "unique" function

[Peter G. <pe...@gm...>]

On 21/12/2007, at 11:52 PM, Bjorn Bringert wrote:

> On Dec 21, 2007, at 17:43 , Justin Bailey wrote:
>> Things I'd like to do still:
>>
>> * Representation of foreign-key relationships (ideally extracted
>> from the DB)
>
> I believe Peter Gammie has some code for foreign key constrains.
> Peter: is that ready to be pulled into HaskellDB?

I can email you (== anyone who's interested) a patch that begins down  
that road. Roughly, I added support for defaults, foreign keys and  
primary keys. IIRC one can create tables with those things but the  
reflection is a bit weak, and the data description types are not  
fantastically robust. (The fieldnames are merely strings, e.g.)

I haven't touched it for a few months now, as I decided it was less  
hassle to just use an SQL script.

You will also need to renovate whatever DB backends you care about.  
(All Haskell DB bindings I looked at act as SQL bridges and treat  
tables merely as tuples.) I added some stuff to HSQL/PostgreSQL, and  
can email you those patches too, if you like. (I could port those to  
another <DB backend>/PostgreSQL if you can convince me there is some  
advantage in doing so - HSQL seemed to be simple, stable, etc. when I  
was looking into these things.)

BTW what state is DBDirect in? I cannot compile hs-plugins (using GHC  
6.6.1) presently, and I don't know what the future holds for that.

Also BTW, I have some not-so-great patches that allow one to do  
character decoding/encoding at the database interface. I use these to  
get PostgreSQL to speak UTF-8. They seem to work well, if not  
particularly cleanly or efficiently. I think some refinement is not  
too much trouble if anyone is interested.

cheers
peter