Introduction:
-------------

The PyQueryBuilder is a project to build SQL queries out of provided
Query Language (QL) expresions. This project has been started within
CMS High-Energy Physics collaboration (CERN, Geneva, Switzerland) to 
provide access to CMS Data Bookkeeping System. It was used as general
purpose Data Discovery service. 

We decided to take it apart from CMS infrastructure and create a
general purpose QL builder with intention to be transparent to DB back-end
and underlying schema implementation.

For more information about it please refer to the following paper:
The CMS Dataset Bookkeeping Service Query Language (DBSql)
By A. Afaq, V. Kuznetsov, L. Lueking, D.Riley, V. Sekhri 
CMS CR-2009/076, To be published in CHEP 2009 procedings.

Credits:
--------
The idea of QL was developed by the following team:

- Valentin Kuznetsov, Cornell University
- Andrew J. Dolgert, Cornell University
- Dan Riley, Cornell Univerisity
- Anzar Afaq, FNAL
- Lee Lueking, FNAL
- Vijej Sekhri, FNAL

The actual implementation of PyQueryBuilder was done by
- Valentin Kuznetsov, vkuznet [at] gmail [dot] com
- Andrew J. Dolgert, ajd27 [at] cornell [dot] edu
- Dong Liang, Liangd [at] ihep [dot] ac [dot] cn

Dependencies:
-------------
The PyQueryBuilder depends on the following software:

- sqlalchemy [http://www.sqlalchemy.org] is used as general SQL ORM;
- YAML [http://pyyaml.org/wiki/PyYAMLDocumentation] is used as interchange data format;
- cherrypy web framework [http://www.cherrypy.org]
- cheetah python template framework [http://www.cheetahtemplate.org/]

License:
--------
The PyQueryBuilder is licensed under free BSD license, please see doc/LICENSE
for more information

Usage:
--------
Commandline tools:
       $> export  QB_ROOT=/<path>/PyQueryBuilder
       $> dbsh
WebServer:$
       $> cd PyQueryBuilder
       $> export QB_ROOT=$PWD
       $> python pyquerybuilder/web/web_server.py