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PRESERVE WHITESPACE

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Derby Reference Manual

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the string does not constitute a well-formed document, JAXP throws an error. Derby
catches the error and throws the error as a SQLException.

string-value-expression

Any expression that evaluates to a SQL character type, such as CHAR, VARCHAR,
LONG VARCHAR, or CLOB. The

string-value-expression

argument can also

be a parameter. You must use the CAST function when you specify the parameter
to indicate the type of value that is bound into the parameter. Derby must verify
that the parameter is the correct data type before the value is parsed as an XML
document. If a parameter is specified without the CAST function, or if the CAST is to
a non-character datatype, Derby throws an error.

PRESERVE WHITESPACE

Required keywords that describe how Derby handles whitespace between
consecutive XML nodes. When the PRESERVE WHITESPACE keywords are
used, Derby preserves whitespace as dictated by the SQL/XML rules for preserving
whitespace.

For more information on what constitutes a well-formed XML document, see the following
specification:

http://www.w3.org/TR/REC-xml/#sec-well-formed

Restriction: The SQL/XML standard dictates that the argument to the XMLPARSE
operator can also be a binary string. However, Derby only supports character string input
for the XMLPARSE operator.

Examples
To insert a simple XML document into the

xcol

XML column in the

x_table

table, use

the following statement:

INSERT INTO x_table VALUES
(1,
XMLPARSE(DOCUMENT '
<roster>
<student age="18">AB</student>
<student age="23">BC</student>
<student>NOAGE</student>
</roster>'
PRESERVE WHITESPACE)
)

To insert a large XML document into the

xcol

XML column in the

x_table

table, from

JDBC use the following statement:

INSERT INTO x_table VALUES
(2,
XMLPARSE (DOCUMENT CAST (? AS CLOB) PRESERVE WHITESPACE)
)

You should bind into the statement using the setCharacterStream() method, or any other
JDBC setXXX method that works for the CAST target type.

Usage note

Derby requires that a JAXP parser (such as Apache Xerces) and Apache Xalan are listed
in the Java classpath for the XML functions to work. If either the JAXP parser or Xalan
is missing from the classpath, attempts to use the XMLPARSE operator will result in an
error. In some situations, you may need to take steps to place the parser and Xalan in
your classpath. See "XML data types and operators" in the Derby Developer's Guide for
details.

XMLQUERY operator

XMLQUERY is a SQL/XML operator that you can use to query XML values in SQL.