A parser, pretty printer, and type checker for SQL written in
Haskell. Supports PostgreSQL SQL and PL/pgSQL syntax. BSD licensed.

Purpose
=======

Possible uses of this library include:

* type-checker can help with SQL development and catch bugs which
  aren't statically detected by Postgres
* generating SQL code programmatically/ generating SQL from some other
  source
* transforming SQL code, possibly using quasiquoting, e.g. writing
  PL/pgSQL with less boilerplate, or optimisation rewrites
* viewing the catalog produced by some SQL code

With some extra work:

* generating documentation for SQL code
* support running one dialect of SQL on a different DBMS using
  automatic translation - portable SQL
* typesafe database access from Haskell
* lint or semantic analysis for SQL or PL/pgSQL

Status
======

Pre-alpha. Support for parsing SQL is patchy, but not too
bad. Supports queries/DML and DDL. Here is an extract from the parsing
tests which gives some examples of what can currently be parsed:

* [Parsing examples](ParserTests.html)

The type checker is currently still being fixed after some reworking
of parsing and ast types. It should handle a lot of queries and dml
fine though.

Extract from the type checking tests:

* [Type-checking examples](TypeCheckTests.html)

Currently limited support for quasiquoting, here are the extracts from
the tests:

* [Quasiquotation examples](QuasiQuoteTests.html)

The pretty printer should support everything the parser supports
(i.e. it pretty prints code which both the parser and Postgres
understand).

Catalog information is limited, supports the type checking. Some
information is collected on scalar types, domains, composite types,
casts, tables, views and functions.

Installation
============

This project is currently developed on GHC 7.2.1. 7.0.x should be
fine, 6.12.x might take a small amount of work.

To install use

~~~~~{.sh}
cabal install hssqlppp
~~~~~

Documentation
=============

[Haddock docs](haddock/index.html)

[Examples](examples.txt.html)

[Some notes on hacking on hssqlppp itself](devel.txt.html)

Links
=====

Homepage: <http://jakewheat.github.com/hssqlppp/>

Hackage: <http://hackage.haskell.org/package/hssqlppp>

Repository: <https://github.com/JakeWheat/hssqlppp>

Changes: <https://github.com/JakeWheat/hssqlppp/blob/master/CHANGES>

Reporting issues and feature requests
=====================================

Use the github issue tracker. Please supply an example of SQL which
doesn't parse/typecheck correctly where relevant.

<https://github.com/JakeWheat/hssqlppp/issues>


Provisional future plans
========================

* parameterized statements/typesafe haskell access
* some simple syntax extension support for SQL
* a 'compiler' command to help developing SQL
* parse most Postgres syntax, possibly other SQL dialects as well
* improve the typechecker - fix current regressions, get more sql type
  checking correctly
* improve the catalog - add more checking, more item types
* improve the quasi-quoting - is a bit ad hoc and limited at the moment
* documentation generator for SQL codebases

Contact
=======

Let me know if you're using/ interested in using the library, if you
have any problems, bug reports, or suggestions, etc.. All
contributions, comments and criticism welcome:

jakewheatmail@gmail.com