Derby supports the XML data type and a set of operators that work with the XML data type, but does not provide JDBC support for the XML data type. The XML data type and operators are based on a small subset of the SQL/XML specification.
The XML data type and operators are defined only in the SQL layer.
There is no JDBC-side support for XML data types. It is not possible to bind directly into an XML value or to retrieve an XML value directly from a result set. Instead, you must bind and retrieve the XML data as Java strings or character streams by explicitly specifying the appropriate XML operator as part of the SQL statements:
CREATE TABLE xml_data(xml_col XML);
INSERT INTO xml_data(xml_col) VALUES(XMLPARSE(DOCUMENT ' <name> Derby </name>' PRESERVE WHITESPACE));
SELECT XMLSERIALIZE(xml_col AS CLOB) FROM xml_data;
SELECT '<my_self>' || '<name>'|| my_name ||'</name>' || '<age>'|| TRIM(CHAR(my_age)) ||'</age>'|| '</my_self>' FROM my_non_xml_table;
Additionally, there is no JDBC metadata support for the XML data type.
The XML data type is not allowed in any of the clauses or operations that are described in the section on expressions on LONG data types in Derby and standards.
For the XML operators to work properly, Derby requires that a JAXP parser, such as Apache Xerces, and Apache Xalan are included in the Java classpath. If either the parser or Xalan are missing from the classpath, Derby disallows any XML-related operations.
Most Java Virtual Machines (JVMs) that are version 1.4 or later have a JAXP parser embedded in the JVM. If you are using one of these JVMs, you may not need to add any classes to your classpath. Some exceptions exist: