Data Accessor Functions

The topics in this section discuss and provide sample code for the data-accessor functions.

Understanding fn:data(), fn:string(), and text()

XQuery has a function fn:data() to extract scalar, typed values from nodes, a node test text() to return text nodes, and the function fn:string() that returns the string value of a node. Their use can be confusing. The following are guidelines for using them correctly in SQL Server. The XML instance <age>12</age> is used for the purpose of illustration.

• Untyped XML: The path expression /age/text() returns the text node "12". The function fn:data(/age) returns the string value "12" and so does fn:string(/age).

• Typed XML: The expression /age/text() returns a static error for any simple typed <age> element. On the other hand, fn:data(/age) returns integer 12. The fn:string(/age) yields the string "12".

In This Section

• string Function (XQuery)

• data Function (XQuery)

Zobacz także

Koncepcje

Path Expressions (XQuery)