Some time ago I stumbled upon SQLAlchemy which is a great ORM wrapper library for python. It has a nice syntax I'd like to see in a haskell library as well. SQLAlchemy already provides some lazy features such as loading subitems on access etc. All haskell SQL libraries I know only let you run SQL statements but not much more. To start real business you no longer want to write many SQL commands. Example why it matters: schools - 1:n - teachers - 1:n - pupils If you want to list all schools which have a pupil with age > 3 you'd write an sql query like this: SELECT dictinct * FROM schools as s JOIN teachers t ON (t.school_id = s.id) JOIN pupils as p ON (p.teacher_id = t.id) WHERE p.age > 3 in SQLAlchemy it looks like this: session.query(School).join(School.teachers).join(Teacher.pupils).filter(Pupil.age > 3).all() difference? Because SQLAlchemy knows about the relations you don't have to remember alias names. So there is no chance to get that wrong. Another example: Updating the age of a pupil: row = SELECT * FROM pupils where age = 13; UPDATE pupils SET age = 14 WHERE id = <the id you got above> p = session.query(Pupil).filter(Pupil.age==13).one().age=14 session.commit() difference? You don't have to care about ids. you just assign a new value and tell the engine that it should commit. So again less chances to get something wrong. What about trees (eg web site navigation) id | title | parent_id 1 | top | null 2 | submenu | 1 3 | submenu2 | 1 should result in top - submenu - submenu2 using SQLAlchemy you can just do parent = session.query('nodes').filter(Node.id = 1) def print(node): print node.title print node.subnodes # this will run a subquery automatically for you returning submenu{,2} Again no sql. No chance to get something wrong? You can skim the manual to get a better idea how SQLAlchemy works http://www.sqlalchemy.org/docs/05/sqlalchemy_0_5_5.pdf I have to admit that I haven't used SQLAlchemy in a real project yet. However I can imagine doing so. Comparing this to what we have on hackage I'd say some work has to be done to get close to SQLAlchemy. The backend doesn't have to be a relational database. However I'd like to use this kind of abstraction in haskell. Is there anyone interested in helping building a library which a) let's you define kind of model of you data b) let's you store you model in any backend (maybe a relational database) c) does static checking of your queries at compilation time? Right now I'd say the best way to go is define the model in the application and not get the scheme from an existing database because there is not way to store all scheme details within a relational model. I think SQLAlchemy does it right by providing a way to define the model in python. Of course haskell doesn't have "objects" to store. But GADTs could be stored (data Foo = ...) So are there any volunteers who are interested in helping writing this kind of storage solution for haskell which could be used in real world business apps? Maybe this does already exist and I've missed it? Marc Weber