Dataquay

Simple RDF for C++ and Qt applications

Dataquay is a free open source library that provides a friendly C++ interface to an RDF datastore using Qt5 or Qt6 classes and containers. Supported datastores are the popular and feature-complete Redland and the lightweight Sord.

Dataquay is simple to use and easy to integrate. It is principally aimed at Qt-based applications that would like to use an RDF datastore as backing for in-memory project data, to avoid having to invent file formats or XML schemas and to make it easy to augment the data with descriptive metadata pulled in from external sources. It's also useful for applications with ad-hoc needs for metadata management using RDF sources.

Dataquay does not use a separate database, instead using in-memory storage with separate file import and export facilities. Although it offers a choice of datastore implementations, the choice is made at compile time: there is no runtime module system to take into account when deploying your application.

Dataquay provides these features:

Simple and flexible storage, lookup, query, and file I/O natively using the RDF Turtle format.
Conversion between arbitrary data types and RDF nodes. Basic types and QVariant data types are converted to XSD datatypes where possible, using an easily extended mechanism.
Optional transactional interface. Transactions are atomic at the library level, and are isolated from any other lookup or other transactions occurring at the same time.
An object mapper facility which can take care of a hierarchy of QObject-derived objects, map it to RDF data, and synchronise in both directions during the lifetime of the object hierarchy or the store. This is flexible enough that it can even be used to load publicly available linked-data sources straight into appropriate class hierarchies, should you wish.
API documentation, thread safety, documentation of threading requirements, readable code, and basic unit tests included.
BSD licensing. You can use Dataquay cost-free in commercial or open source applications and modify it as you like with no particular requirements except acknowledgement in your copyright notes. We do ask that you let us know of any bugs, fixes and enhancements you might find — particularly for serious bugs — but you have no obligation to do so.

Much of the real work in Dataquay is done by the datastore implementation, with credit to Dave Beckett for his excellent Redland C libraries and David Robillard for the Sord library and for the Redland Trees store and Turtle I/O implementations. You will need to have the Raptor, Rasqal and Redland libraries, or Sord and Serd, installed in order to build and use Dataquay.

Big caveat: Dataquay was written for use in serious applications, but it is still an early release and the API may continue to change until the 1.0 release is reached.

Download

	Dataquay v0.9.5 source code Download the source, with qmake project file
	Visit the Dataquay code project Including source code browser and issue tracker