Interstage Shunsaku Data Manager Application Development Guide - Microsoft(R) Windows(R) 2000/ Microsoft(R) Windows Server(TM) 2003 - - UNIX -

B.3.8 Filter Expressions

Filter expressions are used to specify search conditions within the closed range of element nodes specified by the path expressions.

The definition format for filter expressions is shown below.

[Figure B-18 Filter Expression Definition]

• Filter expressions must have two or more conditional expressions.
• Filter expressions can be nested within other filter expressions with up to eight levels of nesting.

Example

An example search expression containing filter expressions is shown below.

Document A

<root>
  <company>
    <employee position="manager">
      <name>smith</name>
      <id>1000</id>
      <skill kind="0017">2005.1</skill>
      <skill kind="0023">2002.3</skill>
      <skill kind="0009">1998.8</skill>
</employee>
  </company>
  <company>
    <employee position="chief">
      <name>jones</name>
      <id>2000</id>
      <skill kind="0033">2004.7</skill>
      <skill kind="0012">2001.9</skill>
    </employee>
  </company>
</root>

Document B

<root>
  <company>
    <employee position="chief">
      <name>smith</name>
      <id>2000</id>
      <skill kind="0002">2003.2</skill>
      <skill kind="0010">2002.3</skill>
    </employee>
  </company>
  <company>
    <employee position="manager">
      <name>jones</name>
      <id>3000</id>
      <skill kind="0001">1995.2</skill>
    </employee>
  </company>
</root>

Search Expression 1

/root/company/employee{/name = '^smith' AND /id = '1000'}

Result

Document A matches the condition but Document B does not.

Treat '/root/company/employee' as a single block. Document A contains data that matches the conditions in braces (/name = '^smith' AND /id = '1000'), while Document B does not.

Search Expression 2

/root/company/employee{/@position = '^manager' AND /id = '3000'}

Result

Document B matches the condition but Document A does not.

Search Expression 3

/root/company/employee/skill{/@kind = '^0001' AND /text() = '1995.2'}

Result

Document B matches the condition but Document A does not.

• Add '/text()' at the end of the conditional expression when specifying the text node in the filter expression.

  Example

  The following example shows the search expression that a filter expression contains text expressions.

  /root/company/employee/skill{/text() = '1995.2' AND /@kind = '0001'}

  
  

  Evaluates to TRUE if the value of the text node in the element node represented by '/root/company/employee/skill' is '1995.2' and the value of the attribute node is '0001'.

• The '*' path element cannot be specified as the final element of the path expressions used in filter expressions. Always specify an element name.

  Example

  In the following example, an error will occur because '*' is specified as the final path element of the path expression.

  /root//company/*{/name = '^smith' AND /id = '1000'}