IVOA Query Language (historic pages) 
 New VOQL group pages 
If you are interested in participating in the definition of the VO Query Language, you are invited to enroll in the Virtual Observatory Query Language Working Group (
voql@ivoa.net).
We have a 3 layer model for VOQL as represented below.
 
Based on the Pune (2004) agreement,In the Boston 2004 meeting, the working document toward a Proposed Recommendation was published. There have been a few minor changes since Pune. This version is to be discussed at Kyoto  
 
The January demos ran on ADLQ0.7.4. But we should be moving to this new version now. dev.openskyquery.net is runnind ADQL0.9
The document was created based on the Boston 2004 agreement, however, several new features, such as CREATE,INSERT,UPDATE,DELETE, have not yet been included because these will actually create a huge increase in the size of the grammar. 
The process of generating the 
ADQL schema  are described in 
ADQL Schema generation steps.
An example XSL style sheet for converting 
ADQL/x to 
ADQL/s (strings) has been provided by NCSA 
adql2sql-ns.xsl.
A pack of XSLT stylesheets for converting 
ADQL to SQL (provided by ESAC) can be downloaded here : 
ADQL2SQL-XSLTs.zip. 
This pack includes stylesheets for v0.7.4 and v1.0 (+ extensions for Mysql and Sybase). 
The latter version works fine for v0.8 and v0.9, just by changing the namespace declaration. 
The currect translation services are for 0.7.4 and are at 
http://openskyquery.net/adqltranslator 
A 
java client for the translation service has been prepared.
SkyNodes and the 
SkyNode portal would form layer 2 and 1 of this system. At the Strasbourg meeting the skynode spec was split in two.
Since release of the Standard Interfaces this has also been reomved from skynode. Finally the portal section has also been reomved leaving a leaner Skynode document. 
 
Latest 
SkyNode WSDL from IVOA 
SkyNode0_9.wsdl
There are currently Java and .NET implementations of this. Nodes are registered in the 
Registry and may be intereacted with through the 
OpenSkyQuery Portal. You may get the .NET version off the help pages of openskyquery. The Basic Java version is included in the 
SumerSchool software from the nvo. 
A More Complete Java implelemtation is underconstruction by Tom McGlynn and is in the 
NVO CVS   under 
contrib/tam/skynode 
Other groups (JVO, ESA, IndiaVO) are also looking at the java implementation.
 SkyNode Registry Schema Extention 
The 
SkyNode also requires a registry entry you may register in the
NVO registry. The schema for the
SkyNode registry entry is here - 
OpenSkyNode-v0.1.xsd
Comments should be posted on the VOQL mailing list as specified below.
 VOQL Sessions in Kyoto 2005 May 
  
 WG Roadmap 
 
-  May 16-20 2005    Interop Kyoto
-- work toward Recommendations 
ADQL/SkyNode 1.0
 
-  June         Prepare PR documents
-- Below is work for future version --
 
-  Sept 2005      First WD ADQL/SkyNode 1.x 
 
-  Integration of current ADQL and DAL (with DAL)
 
-  X-Matcher (with DM/DAL)
 Algorithms, PSF/Baem sizes, Positional errors
 X-match is a part of SkyNode spec, or is an independent application ?
 
-  Inclusion of simulated data access ? (with Registry WG/Theory IG)
 Theory meta data, "coordinate" ?, etc.
 
 
-  Oct 2005    ADASS + IVOA Interop Madrid, Spain
 Discussion on the draft, and revise the WD
-  Spring 2006      reference implementations ?
-  Aug 2006       IAU Prague : VO Special Session
-  Autumn 2006   Interop WS 
 To PR ????
 Mailing-list 
 
-  General working-group discussion archive.
 Related Links 
  
 References 
 
-  Budavári, T., et al. 2002, ADASS XII, O10-1
-  Malik, T., et al. 2002, CIDR `03, p.17, "SkyQuery: A Web Service Approach to Federate Databases"
-  Budavári, T., et al. 2003, ADASS XIII, P2-18