[Haskell-cafe] Haskell and Databases

[Yves P----]

There is something that bothers me with that text, I can't get to grasp what
it is...

2011/7/1 Tobias Schoofs <tobias.schoofs at gmx.net>

> **
> I am studying Haskell database libraries.
> In particular I am looking at
> haskelldb and the Takusen Database.Enumerator library.
>
> In haskelldb, there are very good ideas aiming to represent database
> objects as (typeable) Haskell objects, instead of embedding SQL in plain
> strings.
> This is really an interesting approach that overcomes the hiatus between
> the database there and the processing logic here.
>
> Unfortunately, the library cannot deal with some obvious issues related to
> this concept;
> conflicts arise, for instance, when Haskell keywords are used as names of
> attributes or tables or when the same name is used for an attribute and for
> a table (which is perfectly legal in SQL).
> Also, haskelldb cannot cope with peculiarities of popular database tables,
> such as ISAM tables - which are case sensitive.
>
> Another, more conceptual issue, is the lack of database cursors.
> Database programs, usually, do not just issue isolated SQL statements, but
> implement a processing logic with nested queries and DML statements. A DB
> library should provide control structures to ease this kind of processing.
>
> A library that tackles this issue, is the Takusen Database.Enumerator,
> again, a library with very strong ideas.
> Unfortunately, in Takusen there is nothing like the haskelldb DSL.
>
> Concerning, cursors, Takusen uses iterators to stream query results.
> This makes a lot of sense.
> The iterators, however, cannot be used to implement the nesting of queries.
>
> The user has to provide an additional action which is responsible for all
> the cursor-related logic.
> The tools provided to deal with cursors resemble very much the instructions
> found in other database-oriented languages, such as PL/SQL.
> This leads to verbose code where cursor control is implemented in a quite
> "imperative" way.
> The user, however, should be concerned with getting her queries right, not
> with the "technical" details of fetching from cursors.
>
> In summary, what I miss is a database library that
> - integrates haskelldb approach with
> - a "functional-style" cursor concept
>
> Is anybody working on something like this?
>
> Thanks,
>
> Tobias
>
>
> _______________________________________________
> Haskell-Cafe mailing list
> Haskell-Cafe at haskell.org
> http://www.haskell.org/mailman/listinfo/haskell-cafe
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/haskell-cafe/attachments/20110701/a5681170/attachment.htm>