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

B.4.4 Example Return Expressions used when Aggregating

Some example return expressions are shown below.

Document A

<doc>
  <companyname>fujitsu</companyname>
  <employee position="manager">
    <name>smith</name>
    <id>2000</id>
    <age>30</age>
    <comment></comment>
  </employee>
</doc>

Document B

<doc>
  <companyname>fujitsu</companyname>
  <employee position="chief">
    <name>jones</name>
    <id>1000</id>
    <age>35</age>
    <comment>team leader</comment>
  </employee>
</doc>

Example 1: Example of the avg Function

Return Expression

avg(/doc/employee/age/text())

Sort Expression

/doc/companyname/text()

Result

32.5

Example 2: Example of the count Function that the attribute expression is specified

Return Expression

count(/doc/employee/@position)

Sort Expression

/doc/employee/text()

Result

2

If multiple return items are specified, the value of each return item contained in the result will be separated by the delimiter.

• For Java APIs
  • Extracting the results of searches using the getString or getStream method:
    • The values returned by each return item will be separated with commas ",".
  • Extracting the results of searches using the getStringArray method:
    • Results will be returned as a two dimensional array for each return item.
    • The number of elements in the upper array will be the number of return expressions. There will be one element in the lower array.
• For .NET APIs
  • Extracting the results of searches using the Data properties or getStream method:
    • The values returned by each return item will be separated with the 0x0001 of the hexadecimal number
  • Extracting the results of searches using the getDividedData method
    • Results will be returned as a jagged string array for each return item.
    • The upper array is equal to the number of return expressions. The number of elements in the lower array is 1.
• For C APIs
  • The values returned by each return item will be separated with the character code "\001".
  • The character "\001" will always be appended to the end of the values returned.

Example 3: Example of Specifying Multiple Return Items

Return Expression

avg(/doc/employee/age/text()),count(/doc/employee/name/text())

Sort Expression

/doc/companyname/text()

Result

32.5,2

If the text node specified with the expression or the attribute node specified with the attribute expression occurs more than once in the same document, only the value of the first text node or the value of attribute node will be used.

Example

In the following example, the text expression '/student/subject/test/score/text()' is passed as an argument to the avg function. In this case, Document A will not be included in the aggregation target, the value of Document B will be treated as 80, and Document C will be 0.

Document A

<student>
  <name>smith</name>
  <subject>
    <subjectname>science</subjectname>
  </subject>
  <name>smith</name>
</student>

Document B

<student>
  <name>jones</name>
  <subject>
    <subjectname>science</subjectname>
    <test>
      <date>2006/01/12</date>
      <score>80</score>
    </test>
    <test>
      <date>2005/12/08/</date>
      <score>70</score>
    </test>
  </subject>
</student>

Document C

<student>
  <name>murphy</name>
  <subject>
    <subjectname>science</subjectname>
    <test>
      <date>2006/01/12</date>
      <score>--</score>
    </test>
  </subject>
</student>

Return expression

avg(/student/subject/test/score/text())

Sort expression

/student/subject/subjectname/text()

Result

40