Categories:: Semi-structured Data Functions (Parsing)

CHECK_XML¶

Checks the validity of an XML document. If the input string is NULL or a valid XML document, the output is NULL. In case of an XML parsing error, the output string contains the error message.

See also:: PARSE_XML

Syntax¶

CHECK_XML( <string_containing_xml> [ , <disable_auto_convert> ] )

Arguments¶

Required:

string_containing_xml: This expression should evaluate to a VARCHAR. The VARCHAR should contain valid XML.

Optional:

disable_auto_convert

Specify the same value that you pass to the PARSE_XML function.

Default: FALSE

Returns¶

The data type of the returned value is VARCHAR.

Examples¶

Show the Output of the Function When the XML is Valid¶

SELECT CHECK_XML('<name> Valid </name>');
+-----------------------------------+
| CHECK_XML('<NAME> VALID </NAME>') |
|-----------------------------------|
| NULL                              |
+-----------------------------------+

Show the Output of the Function When the XML is Invalid¶

SELECT CHECK_XML('<name> Invalid </WRONG_CLOSING_TAG>');
+--------------------------------------------------+
| CHECK_XML('<NAME> INVALID </WRONG_CLOSING_TAG>') |
|--------------------------------------------------|
| no opening tag for </WRONG_CLOSING_TAG>, pos 35  |
+--------------------------------------------------+

Locate Records With Invalid XML¶

SELECT xml_str, CHECK_XML(xml_str)
    FROM my_table
    WHERE CHECK_XML(xml_str) IS NOT NULL;