Brief introduction to Opaleye
Opaleye is a Haskell library which provides an SQL-generating embedded
domain specific language for targeting Postgres. You need Opaleye if
you want to use Haskell to write typesafe and composable code to query
a Postgres database.
Opaleye allows you to define your database tables and write queries
against them in Haskell code, and aims to be typesafe in the sense
that if your code compiles then the generated SQL query will not fail
at runtime. A wide range of SQL functionality is supported including
inner and outer joins, restriction, aggregation, distinct, sorting and
limiting, unions and differences. Facilities to insert to, update and
delete from tables are also provided. Code written using Opaleye is
composable at a very fine level of granularity, promoting code reuse
and high levels of abstraction.
Tutorials
Please get started with Opaleye by referring to these two tutorials
Contact
Contact the author
The main author of Opaleye is Tom Ellis. He can be contacted via
email.
File bugs
Please file bugs on the Opaleye GitHub issue tracking
page.
Mailing list
Please join the opaleye-users mailing
list.
Internal modules
Opaleye exports a number of modules named Opaleye.Internal.....
They are provided in case of urgent need for access to the internals,
but they are not intended to be used by API consumers and if you find
yourself repeatedly accessing them this is a sign that either you or
Opaleye are doing something wrong. In such a case please file a bug.
The interface of Internal modules does not follow the PVP and may
break between minor releases, so be careful.
Commercial support
Commercial support for Opaleye is provided by Purely
Agile.
Contributors
The Opaleye Project was founded by Tom Ellis, inspired by theoretical
work on databases by David Spivak. Much of the implementation was
based on ideas and code from the HaskellDB project by Daan Leijen,
Conny Andersson, Martin Andersson, Mary Bergman, Victor Blomqvist,
Bjorn Bringert, Anders Hockersten, Torbjorn Martin, Jeremy Shaw and
Justin Bailey.
Silk (Erik Hesselink, Adam Bergmark), Karamaan (Christopher Lewis),
Fynder (Renzo Carbonara, Oliver Charles) and Daniel Patterson
contributed code to the project.
Joseph Abrahamson, Alfredo Di Napoli and Mietek Bak performed useful
reviews of early versions which helped improve the codebase.
