Add a search field that searches another module

Anybody know, how to do it for 7.8.15 version?
There is an article for this. But when i try it for 7.8.15, it does not work.
Add a search field that searches another module

I don’t know much about this…

Do you get any PHP errors in php_errors.log?

According to log ;

Query Failed:  SELECT  contacts.id , contacts.assigned_user_id , LTRIM(RTRIM(CONCAT(IFNULL(contacts.first_name,''),' ',IFNULL(contacts.last_name,'')))) as name, contacts.first_name , contacts.last_name , contacts.salutation  , accounts.name account_name, jtl0.account_id account_id, contacts.title , contacts.phone_work , contacts.date_entered , contacts.primary_address_country  , jt1.user_name assigned_user_name , jt1.created_by assigned_user_name_owner  , 'Users' assigned_user_name_mod, contacts.created_by  FROM contacts  LEFT JOIN contacts_cstm ON contacts.id = contacts_cstm.id_c   LEFT JOIN  accounts_contacts jtl0 ON contacts.id=jtl0.contact_id AND jtl0.deleted=0

 LEFT JOIN  accounts accounts ON accounts.id=jtl0.account_id AND accounts.deleted=0
 AND accounts.deleted=0  LEFT JOIN  users jt1 ON contacts.assigned_user_id=jt1.id AND jt1.deleted=0

 AND jt1.deleted=0 where ((contacts.id IN (SELECT nn.contact_id FROM notes nn INNER JOIN notes_cstm nc  on nn.id=nc.id_c where nn.deleted=0 AND nc.eventyear_c=))) AND contacts.deleted=0 ORDER BY name ASC LIMIT 0,51: MySQL error 1064: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '))) AND contacts.deleted=0 ORDER BY name ASC LIMIT 0,51' at line 6

But my sql is just;

SELECT nn.contact_id FROM notes nn INNER JOIN notes_cstm nc  on nn.id=nc.id_c where nn.deleted=0 AND nc.eventyear_c=

When i run this sql on Query, it is working good;

SELECT nn.contact_id FROM notes nn INNER JOIN notes_cstm nc  on nn.id=nc.id_c where nn.deleted=0 AND nc.eventyear_c='2014'

Well it doesn’t seem to have a value there for the year… can you check your code generating this?

nc.eventyear_c=)))