选择最大值和对应的列

Question

I am trying to grab the max date from the updates column but also return the corresponding fullname from that table, what is currently happening is that the latest updates.date is being returned but the first updates.consultant is currently being returned as well and we need the correct fullname for the MAX date.

SELECT customer.id, 
       customer.name, 
       customer.retainer_value, 
       customer.customer_type, 
       clientdetails.performance, 
       clientdetails.url, 
       members.fullname AS acc_manager, 
       u.maxdate, 
       u.fullname 
FROM   customer 
       LEFT JOIN clientdetails 
              ON clientdetails.id = customer.id 
       LEFT JOIN members 
              ON members.id = customer.consultant_name 
       LEFT JOIN (SELECT updates.clientid, 
                         members.fullname, 
                         Max(updates.`date`) AS MaxDate 
                  FROM   updates 
                         LEFT JOIN members 
                                ON members.id = updates.consultant 
                  GROUP  BY updates.clientid 
                  ORDER  BY updates.date DESC) u 
              ON customer.id = u.clientid 
WHERE  customer.switchedoff = 'N' 
       AND customer.companyid <> '3' 

Answer 1

I think the easiest way in your case is to use the substring_index() / group_concat() method:

SELECT customer.id, 
       customer.name, 
       customer.retainer_value, 
       customer.customer_type, 
       clientdetails.performance, 
       clientdetails.url, 
       members.fullname AS acc_manager, 
       u.maxdate, 
       u.fullname 
FROM   customer 
       LEFT JOIN clientdetails 
              ON clientdetails.id = customer.id 
       LEFT JOIN members 
              ON members.id = customer.consultant_name 
       LEFT JOIN (SELECT updates.clientid, 
                         substring_index(group_concat(m.fullname order by u.date desc separator '|'), '|', 1) as full_name
                         Max(updates.`date`) AS MaxDate 
                  FROM   updates u
                         LEFT JOIN members m
                                ON m.id = u.consultant 
                  GROUP  BY u.clientid
                 ) u 
              ON customer.id = u.clientid 
WHERE  customer.switchedoff = 'N' 
       AND customer.companyid <> '3' ;