Learn note updatexml () MySQL explicit error injection

Before you learn, you need to know Updatexml ().

Updatexml (Xml_document, xpath_string, New_value);
The first parameter: Xml_document is a string format, the name of the XML Document object, and the doc
The second argument: Xpath_string (a string in XPath format), you can find tutorials online If you don't know the XPath syntax.
Third parameter: new_value,string format, replacing found eligible data
Action: Change the value of a node in the document that matches the criteria

And then we'll look at the statement:

http://www. xxxiii.com/a.php?id=1 and Updatexml (1, concat (0x7e, (  SELECT@ @version),0x7e),1)

CONCAT (STR1,STR2,...)

Returns the string that results from the connection parameter. If any one of the arguments is NULL, the return value is null.

Returns the version by querying @ @version. The concat then strings it. Because the Updatexml second parameter requires an XPath-formatted string, it does not meet the requirements, and then an error is given.

The error will probably be:

1105 (HY000): XPATH syntax error: ': root@localhost'

The string that does not understand the XPath format comes here: http://www.cnblogs.com/Loofah/archive/2012/05/10/2494036.html

Learn note updatexml () MySQL explicit error injection