Chapter 18. Working with Strings
Strings are probably the most used type of atomic values in queries. This chapter discusses constructing and comparing strings and provides an overview of the many built-in functions that manipulate strings. It also explains string- and text-related features such as whitespace handling and internationalization.
The basic string type that is intended to represent generic character data is called, appropriately,
xs:string type is not the default type for untyped values. If a value is selected from an input document with no schema, the value is given the type
xs:string. However, it is easy enough to cast an untyped value to
xs:string. In fact, you can cast a value of any type to
xs:string and cast an
xs:string value to any type.
xs:string type is a primitive type from which a number of other types are derived. All the operations and functions that can be performed on
xs:string values can also be performed on values whose types are restrictions of
xs:string. This includes user-defined types that appear in a schema, as well as built-in derived types such as
xs:ID. For a complete explanation of the built-in types, see Appendix B.
There are three common ways to construct strings: using string literals, the
xs:string constructor, and the
Strings can be included in queries as literals, using double or single quotes. For example, ...