Data sequences are one of the most basic data models used in XML. However, manipulating them can be nontrivial. One of the most common data sequence patterns used in BPEL process service components are arrays. Based on the XML schema, the way you can identify a data sequence definition is by its attribute maxOccurs being set to a value greater than one or marked as unbounded. See the XML Schema Specification at http://www.w3.org/TR for more information.

The examples in this section illustrate several basic ways of manipulating data sequences in BPEL. However, there are other associated requirements, such as performing looping or dynamic referencing of endpoints. The following sections describe a particular requirement for data sequence manipulation.