xquery-path-expressions-specifying-predicates

          declare @x xml
          set @x = '
          <People>
          <Person>
          <Name>John</Name>
          <Age>24</Age>
          </Person>
          <Person>
          <Name>Goofy</Name>
          <Age>54</Age>
          </Person>
          <Person>
          <Name>Daffy</Name>
          <Age>30</Age>
          </Person>
          </People>
          '

        

As described in the topic,

Path Expressions in XQuery

, an axis step in a path expression includes

the following components:

An axis.

A node test. For more information, see

Specifying Node Test in a Path Expression Step.

Zero or more predicates. This is optional.

The optional predicate is the third part of the axis step in a path expression.

A predicate is used to filter a node sequence by applying a specified test. The predicate

expression is enclosed in a square bracket and is bound to the last node in a path expression.

For example, assume that a SQL parameter value (x) of the

data type is declared, as shown

in the following:

In this case, the following are valid expressions that use a predicate value of [1] at each of three

different node levels:

declare @x xml set @x = '
<People>
<Person>
<Name>John</Name>
<Age>24</Age>
</Person>
<Person>
<Name>Goofy</Name>
<Age>54</Age>
</Person>
<Person>
<Name>Daffy</Name>
<Age>30</Age>
</Person>
</People>
'