Erreur MySQL : Unknown column 'E' in 'where clause'

Requête originale : select page_id from wagaia_301 where url='3dParty/rs-plugin/js/'+E+''

#0  Database->error(select page_id from wagaia_301 where url='3dParty/rs-plugin/js/'+E+'', ) called at [/home/formatioczw/www/wagaia/php/mysqli.class.php:268]
#1  Database->query(select page_id from wagaia_301 where url='3dParty/rs-plugin/js/'+E+'') called at [/home/formatioczw/www/wagaia/php/mysqli.class.php:240]
#2  Database->toArray() called at [/home/formatioczw/www/wagaia/php/mysqli.class.php:222]
#3  Database->select(select page_id from wagaia_301 where url='3dParty/rs-plugin/js/'+E+'') called at [/home/formatioczw/www/wagaia/php/mysqli.class.php:282]
#4  Database->get(select page_id from wagaia_301 where url='3dParty/rs-plugin/js/'+E+'') called at [/home/formatioczw/www/config/queries.php:24]
#5  require(/home/formatioczw/www/config/queries.php) called at [/home/formatioczw/www/index.php:3]