XQuery is an XML-based query language for extracting information from structured and unstructured data, typically – but not limited to – XML format. XQuery is supported by dozens of applications and software tools, and is commonly used wherever XML data is exchanged, consumed, or otherwise processed.
Now Altova is proud to announce launch of the first comprehensive XQuery online training, including the latest features of XQuery 3.1. Altova’s free online XQuery tutorial is available now at the Training and Tutorials section of the Altova Web site.
The Altova online XQuery Tutorial and Training Course covers in detail all features of XQuery 3.1, the most recent specification published by the World Wide Web Consortium (W3C).
The XQuery FLOWR expression is the core of the XQuery language and is equivalent to a SELECT statement in SQL. The acronym FLOWR is based on clauses of the expression: for, let, order by, where, and return. A simple FLOWR expression from an example in the XQuery online training is shown below.
A major unit in the XQuery Tutorial and Training Course covers FLOWR expressions and all their options and variations.
Constructors are used to create XML elements, attributes, documents, text, comments, or processing instructions inside XQuery expressions. The Altova XQuery Online Training covers both direct constructors and computed constructors, using examples like the one shown here:
Computed constructors are extremely powerful, but can be difficult for inexperienced users to grasp. The Altova XQuery Tutorial and Training Course contains extensive examples, including enclosed expressions in computed element constructors.
Consuming JSON with XQuery
XQuery 3.1 provides two built-in functions to parse JSON data: parse-json() and json-doc(). Both are covered extensively in a dedicated chapter of the Altova XQuery Online Training.
XQuery Support in XMLSpy
When you’re ready to write your own XQuery expressions, XMLSpy, the world’s leading XML tool with the most advanced XPath and XQuery development features, is a great place to start. When you open an XQuery document in XMLSpy, Helper windows provide quick access to XQuery keywords, XQuery functions, and a list of XQuery variables in the document. The XPath/XQuery output window in XMLSpy lets you build and evaluate XQuery expressions on the fly. And if you don’t get the results you expect, you can enter Debug mode, with support for breakpoints and tracepoints that let you go step-by-step through the evaluation.
XQuery Support in MobileTogether
The XPath and XQuery languages play a crucial part in the design of mobile apps built with MobileTogether, the affordable, cross-platform mobile development framework from Altova. XPath is used to locate, access, manipulate, generate, and save data in the various data trees used in the app design and to define the functioning of different design components.
In the screenshot of the design of a mobile app below, the developer chose to select bold and underline text properties of the button labeled Month to Date by XPath expressions, and the size property is set by an XQuery function.
Don’t let the above simple example fool you, though. MobileTogether unlocks the full power of XQuery as a functional programming language. For example, the screenshot below shows the definition of an XQuery function that calculates the driver’s distance to the next destination in the example Parcel Delivery app installed with the MobileTogether Designer. The function definition from the MobileTogether intelligent XPath/XQuery editor is superimposed over a view of the app running in the Simulator window.
Data sources for mobile apps built with MobileTogether are provided in XML, JSON, HTML format, or as database data. Regardless of the original format, all data sources can be manipulated using XQuery expressions.
Whether you are new to XQuery, already know the basics and you’re looking for a deeper dive, or you just want to cover the latest new features, the self-paced comprehensive Altova XQuery Tutorial and Training is your starting point for XQuery excellence!