db2-xdb:column decomposition annotation

Annotation type

Attribute of <xs:element> or <xs:attribute>, or child element of <db2-xdb:rowSetMapping>

How to specify

db2-xdb:column is specified in any of the following ways (where value represents a valid value for the annotation):

• <xs:element db2-xdb:rowSet="value" db2-xdb:column="value" />
• <xs:attribute db2-xdb:rowSet="value" db2-xdb:column="value" />

• <db2-xdb:rowSetMapping>
     <db2-xdb:rowSet>value</db2-xdb:rowSet>
     <db2-xdb:column>value</db2-xdb:column>
     …
  </db2-xdb:rowSetMapping>

Namespace

http://www.ibm.com/xmlns/prod/db2/xdb1

Valid values

Any base table column name.

Details

• Undelimited column names are case-insensitive.
• When special characters, such as double quotation marks ("), ampersands (&), or less-than signs (<) are part of SQL identifiers, those special characters need to be replaced by their equivalent XML notations. For example, replace " with &quot;, & with &amp;, and < with &lt;.
• db2-xdb:column is an optional child element of db2-xdb:rowSetMapping if the db2-xdb:locationPath annotation is present.

Example

The following example shows how content from the <book> element can be inserted into columns of a table called BOOKCONTENTS, using the db2-xdb:column annotation. A section of the annotated schema is presented first.

<xs:element name="book">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="authorID" type="xs:integer" />
      <xs:element name="chapter" type="chapterType" maxOccurs="unbounded" />
    </xs:sequence>
    <xs:attribute name="isbn" type="xs:string"
                  db2-xdb:rowSet="BOOKCONTENTS" db2-xdb:column="ISBN" />
    <xs:attribute name="title" type="xs:string" />
  </xs:complexType>
</xs:element>

<xs:complexType name="chapterType">
  <xs:sequence>
    <xs:element name="paragraph" type="paragraphType" maxOccurs="unbounded"
                db2-xdb:rowSet="BOOKCONTENTS"
                db2-xdb:column="CHPTCONTENT" />
  </xs:sequence>
  <xs:attribute name="number" type="xs:integer"
                db2-xdb:rowSet="BOOKCONTENTS"
                db2-xdb:column="CHPTNUM" />
  <xs:attribute name="title" type="xs:string"
                db2-xdb:rowSet="BOOKCONTENTS"
                db2-xdb:column="CHPTTITLE" />
</xs:complexType>
  
<xs:simpleType name="paragraphType">
  <xs:restriction base="xs:string"/>
</xs:simpleType>

The <book> element that is being mapped is presented next, followed by the resulting BOOKCONTENTS table after the decomposition has completed.

<book isbn="1-11-111111-1" title="My First XML Book">
  <authorID>22</authorID>
  <!-- this book does not have a preface -->
  <chapter number="1" title="Introduction to XML">
    <paragraph>XML is fun...</paragraph>
    ...
  </chapter>
  <chapter number="2" title="XML and Databases">
    <paragraph>XML can be used with...</paragraph>
  </chapter>
  ...
  <chapter number="10" title="Further Reading">
    <paragraph>Recommended tutorials...</paragraph>
  </chapter>
</book>