title: How to resolve SELECT list is not in GROUP BY clause and contains nonaggregated?
body: <p>I am getting an error with MYSQL 5.7 on this request. How to resolve this error ?</p>
  
  <blockquote>
    <p>#1055 - Expression #3 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'test.c.customers_group_id' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by</p>
  </blockquote>
  
  <pre><code>select  SQL_CALC_FOUND_ROWS  c.customers_firstname, 
                               c.customers_lastname, 
                               c.customers_group_id,
                               sum(op.products_quantity * op.final_price) as ordersum 
  from customers c,
       orders_products op,
       orders o
  where c.customers_id = o.customers_id 
  and o.orders_id = op.orders_id 
  group by c.customers_firstname, 
           c.customers_lastname 
  order by ordersum DESC
  </code></pre>