Jonathan Robie announced Quilt,
"an XML query language
designed for queries on heterogeneous data sources, and
drawing from the design of XQL, XML-QL, SQL, and
OQL," on the XQL
list.
Although the authors (Jonathan Robie, Don Chamberlin and
Dana Florescu) are all members of the W3C XML
Query WG and the language has been designed to meet the
requirements of
the WG, Robie says that:
"Since the Query WG is not yet working on
concrete query languages, it is too early to say how it will
respond to this proposal."
The purpose of the language seems therefore to be to
illustrate the Query WG requirements document with a
general purpose query language:
"Several XML-based query languages have been
proposed, each oriented toward a specific category of
information.
Quilt is a new proposal that attempts to unify concepts from
several of these query languages, resulting in a new
language that
exploits the full versatility of XML."
Quilt which has chosen a "human readable" syntax as
opposed to a "XML based syntax":
"The W3C XML Query Working Group has identified a
requirement for both a human-readable query syntax and an
XML-based query syntax. Quilt is designed to meet the first
of
these requirements. We recognize that an alternative,
XML-based
syntax for the Quilt semantics would be useful for some
applications."
It also includes features to query relational databases:
"for querying
databases, the language needs to provide traditional
database
operations such as joins and grouping."