Non-empty sequences returned by XMLQUERY

If evaluation of the XQuery expression that you specify in XMLQUERY results in a non-empty sequence, the XMLQUERY function returns that sequence.

Example: Suppose that two of the documents in the INFO column of the sample CUSTOMER table look like these:

<customerinfo xmlns="http:⁄⁄posample.org" Cid="1002">
  <name>Jim Noodle<⁄name>
  <addr country="Canada">
    <street>25 EastCreek<⁄street>
    <city>Markham<⁄city>
    <prov-state>Ontario<⁄prov-state>
    <pcode-zip>N9C 3T6<⁄pcode-zip>
  <⁄addr>
  <phone type="work">905-555-7258<⁄phone>
<⁄customerinfo>

<customerinfo xmlns="http:⁄⁄posample.org" Cid="1003">
  <name>Robert Shoemaker<⁄name>
    <addr country="Canada">
    <street>1596 Baseline<⁄street>
    <city>Aurora<⁄city>
    <prov-state>Ontario<⁄prov-state>
    <pcode-zip>N8X 7F8<⁄pcode-zip>
  <⁄addr>
  <phone type="work">905-555-7258<⁄phone>
  <phone type="home">416-555-2937<⁄phone>
  <phone type="cell">905-555-8743<⁄phone>
  <phone type="cottage">613-555-3278<⁄phone>
<⁄customerinfo>

You execute the following statement:

SELECT CID, XMLQUERY ('declare default element namespace "http://posample.org";
  /customerinfo/phone' passing INFO)
 AS "PHONE FROM INFO"
 FROM CUSTOMER
 WHERE CID IN (1002,1003)

The result table contains the following two rows:

Table 1. Example of a result table from XMLQUERY that returns non-empty sequences
CID	PHONE FROM INFO
1002	<?xml version="1.0" encoding="IBM037"?><phone xmlns="http://posample.org" type="work">905-555-7258</phone>
1003	<?xml version="1.0" encoding="IBM037"?><phone xmlns="http://posample.org" type="work">905-555-7258</phone><phone xmlns="http://posample.org" type="home">416-555-2937</phone><phone xmlns="http://posample.org" type="cell">905-555-8743</phone><phone xmlns="http://posample.org" type="cottage">613-555-3278</phone>

The first row contains a sequence of one <phone> element, and the second row has a sequence of four <phone> elements. This result demonstrates that when XMLQUERY returns a sequence that contains more than one element, the serialization process concatenates the elements into a single string. The result in the second row is not a well-formed document. Ensure that any application that receives this result can properly handle this behavior.