SQL query works in mySQL, breaks in Laravel query builder

The problem is that your related table client_contacts can have more than one row which corresponds to a row in the clients table. Even if it won't happen in reality, the db doesn't know that and throws an error.

You have two options

1. Turn off sql_mode=only_full_group_by so that it can pick one row at random and display that
2. Precede each aggregate column with MAX() so that it just gets one of them.

The resulting query would look like this:

SELECT `clients`.name, `clients`.address_1, 
  MAX(`client_contacts`.family_name),
  MAX(`client_contacts`.given_name), 
  MAX(`client_contacts`.office_country),
  MAX(`client_contacts`.office_city), 
  MAX(`client_contacts`.office_number),   
  MAX(`client_contacts`.position), 
  MAX(`contact_titles`.description)
FROM `clients`
INNER JOIN `client_contacts`
ON `clients`.entry = `client_contacts`.client
INNER JOIN `contact_titles`
ON `client_contacts`.title = `contact_titles`.code
GROUP BY `clients`.entry
ORDER BY `clients`.entry ASC;

Try this command in mysql, phpmyadmin then try

SET GLOBAL sql_mode=(SELECT CONCAT(@@sql_mode, ',ONLY_FULL_GROUP_BY'));

And if you using group by then group by column must be present in select query "'clients.entry'"

DB::table('clients')
->select('clients.name', 'clients.address_1', 'client_contacts.family_name',
  'client_contacts.given_name', 'client_contacts.office_country', 
  'client_contacts.office_city', 'client_contacts.office_number', 
  'client_contacts.position', 'contact_titles.description', 'clients.entry')
->join('client_contacts','clients.entry','=','client_contacts.client')
->join('contact_titles','client_contacts.title','=','contact_titles.code')
->groupBy('clients.entry')
->orderBy('clients.entry','asc')
->get();