i have mysql xml field like this
<?xml version="1.0" encoding="UTF-8"?>
<record
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://www.loc.gov/MARC21/slim">
<leader>00764nas </leader>
<controlfield tag="221">011258</controlfield>
<datafield tag="578" ind1=" " ind2=" ">
<subfield code="a">jaun</subfield>
</datafield>
<datafield tag="356" ind1=" " ind2=" ">
<subfield code="a"></subfield>
<subfield code="c"></subfield>
</datafield>
<datafield tag="333" ind1=" " ind2=" ">
<subfield code="d">ali</subfield>
<subfield code="p">22</subfield>
</datafield>
<datafield tag="222" ind1=" " ind2=" ">
<subfield code="c"></subfield>
<subfield code="d">1984</subfield>
</datafield>
</record>
i don't know how to apply SELECT ExtractValue at this field?