mySql WHERE `xml<date>` = '11/21/2010'

i have a mySql database, and it has an field for each entry called xml, which contains XML. i would like to know if there is syntax to 开发者_高级运维select xml values like normal fields.

for example if i wanted to select all entries with the date of 11/21/2010 i try something like this, but the syntax is wrong, since i don't know how to work with xml well in mySql.

SELECT * 
  FROM `table` 
 WHERE `xml<date>` = '11/21/2010'

Ideally, I would like to compare it to another field:

SELECT * 
  FROM `table` 
 WHERE `xml<date>` != `date`

You can use the ExtractValue function with an XPath expression to get your desired field:

SELECT * 
FROM `table` 
WHERE ExtractValue(xml,'/a/suitable/xpath/expression') != `date`