[Koha] El ExtractValue y MarcXML

[Luis Moises Rojas]

Hello everybody
I am trying to use this instruction, but does not work,
i am using koha 17.05.

 ExtractValue(marcxml,'//controlfield[@tag="008"]'), 8,4 ) AS 'PUB DATE'


thanks


-- 
*Luis Moisés Rojas P.*