[Koha] (no subject)

[Javed Sahil]

Hi all,
I am using koha 17.11,
Can anybody help me correcting the syntax?

ExtractValue( marcxml , ''//datafield[@tag="650"]/subfield[@code="a"]'')
AS lcsh FROM biblioitems)

The full code of report is following:

SELECT CONCAT('<a href=\"/cgi-bin/koha/catalogue/detail.pl?biblionumber=
',biblionumber,'\">',biblionumber,'</a>')
AS bibnumber, lcsh
FROM
(SELECT biblionumber, ExtractValue( marcxml ,
''//datafield[@tag="650"]/subfield[@code="a"]'')
AS lcsh FROM biblioitems)
AS subjects
WHERE lcsh LIKE CONCAT( '%', <<Subject>>, '%' )

Regard,
Javed Shoukat