SkyQL(ID:8302/)

Human readable version of ADQL, also ADQL/S
Related languages
ADQL => SkyQL   representation of
References:
  • Yasuda, N.; Mizumoto, Y.; Ohishi, M.; O'Mullane, W.; Budavári, T.; Haridas, V.; Li, N.; Malik, T.; Szalay, A. S.; Hill, M.; Linde, T.; Mann, B.; Page, C. G. "Astronomical Data Query Language: Simple Query Protocol for the Virtual Observatory" Astronomical Data Analysis Software and Systems (ADASS) XIII, Proceedings of the conference held 12-15 October, 2003 in Strasbourg, France. Edited by Francois Ochsenbein, Mark G. Allen and Daniel Egret. ASP Conference Proceedings, Vol. 314. San Francisco: Astronomical Society of the Pacific, 2004., p.293 view details Abstract: The Astronomical Data Query Language (ADQL) is a proposed standard query language for the interoperability of the International Virtual Observatory. The data servers in the International Virtual Observatory could be searched using an ADQL query. The servers would return VOTables as a result of the query. External link: Online copy Extract: SkyQL
    SkyQL
    SkyQL is a string like representation of ADQL. Semantically SkyQL and ADQL
    are identical. Syntactically ADQL is XML and SkyQL is more human readable.
    For example, a simple SkyQL like
    select t.*, b.*
    from Tab t, Bob b
    where t.g <> b.g and
    Region('Circle J2000 12.5 23.0 0.5')
    will be converted to ADQL document of about 70 lines. This is why we
    might like a human readable SkyQL as well as the machine readable ADQL.
    Conversion between ADQL and SkyQL is automatic and sample converter applications
    are available3 4 Extract: Astronomical Data Query Language (ADQL)
    Astronomical Data Query Language (ADQL)
    ADQL is the language for expressing queries against tabular data such as catalogs in the Virtual Observatory. The SkyNode (see below) specification proposes a standard way of passing this query. Since ADQL deals with tabular data it is appropriate for the result of such a query to be a Table. VOTable is an adopted standard of the Virtual Observatory, for providing tabular data. Hence we foresee the minimal requirement on servers that they provide results in VOTable.
    Other formats may also be offered by some nodes.
    ADQL is passed as an XML document to the Query Interface. ADQL is based on a subset of SQL plus Region and XMatch. The only SQL command allowed in ADQL is a \select". We have adopted SQL like language as a first step since many astronomical data currently available are tabular data and they are stored in the relational databases. See the XSD1 and the current proposal specification2 for the complete structure of ADQL.