Welcome to HTSQL

Hyper Text Structured Query Language is a translator from HTTP URLs onto SQL queries. An HTSQL server turns HTTP web requests into the corresponding SQL, executes the results on a server-side database such as PostgreSQL, and returns the results in a format requested. The current implementation of HTSQL is done via Python against PostgreSQL database using WSGI.

Our discussion mailing list is hosted by Google Groups.

Specification

The specification for HTSQL can be found at http://htsql.org/spec/, it is moderately out-of-date. Please also read the paper and poster from ICOMP07 given on Wed, June 27 2007. At this point, the best detailed specification is the regression test found at regress.yaml together with the corresponding data definition schema regress.sql and the expected outputs expect.yaml ; we will update the specification as time permits. Several work-in-progress wiki pages are related:

• Command/Formatter Unification
• HTSQL Query API
• Tree and Forest Requests
• HTSQL Functions:
  • String Functions
  • Boolean Functions
  • Numeric Functions
  • DateTime Functions
  • Null Related Functions
  • Array and Aggregates Functions
  • Identity Related Functions
  • All/Any Proposal
• Plugin Architecture (outdated)
• HTSQL Exceptions (outdated)
• Interaction between Commands and Formatters (outdated, see CommandFormatterUnification)
• JSON Output Described (outdated)
• Roadmap (outdated)

Current Release

The current release of HTSQL is 0.11.1, although new development should be done on 0.12 which is stable and available in trunk. This version is currently being used in production for several projects at the Simons Foundation. This version of HTSQL requires PostgreSQL version 8.3.0 or up.

Development Trunk

Development at http://htsql.org/svn/trunk is focused on refactoring, documentation, maintainability and correctness. The trunk may not work at any given point in time.

Production Release

We expect a final 1.0 release for PgCon?, in May of 2009. This will happen when the documentation has caught up to the state of HTSQL's functionality. We have a significant refactor of the query generator to fix some errors in aggregate construction and also to add forest queries yet to accomplish. While there are known bugs at this time, none of them should prevent production usage.