php select ExtractValue

Hi
when execute this query
<?php
$sqlr ="select *
from biblioitems
where EXTRACTVALUE( marcxml, \ '//datafield[@tag="520"]/subfield[@code="d"]')='' ";

give me this error

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '\ "//datafield[@tag="520"]/subfield[@code="d"]")=""' at line 4

any help??

 

Try:

$sqlr ="select * from biblioitems
where EXTRACTVALUE( marcxml,  '//datafield[@tag=\"520\"]/subfield[@code=\"d\"]')='' ";

Code (markup):

Basically remove the escape string for single quote which I don't see it needed, and add the needed escape for quotes.

 

One thing I noticed immediately was this
marcxml, \ '// <----- This appears to me that you were trying to pass the single quote by putting the \ in front of it.

Yet near the end you had "d"]')='' "; <------ Here you have the what appears to be ending single quote and there is no \

In this statement you should try EXTRACTVALUE( marcxml, ''//datafield[@tag="520"]/subfield[@code=\"d\"]'')='' ";

Thats my guess on this.

 

Couldn't the OP just double up the single quotes?

 

Thanks this query works well