Get latest records with id for each group with latest date-time not id - mysql

Question

• My requirement is to get id based on latest frame (based on date-time) is inserted with group by vehicle id.

I have tried with below query

 select a.id,a.vehicle_id,a.info_datetime 
  from table_name a 
  join (select id, max(info_datetime) as maxdt from table_name group by vehicle_id) as b 
    on a.info_datetime = b.maxdt

• The output will not give the proper id.
• So, I want the id for latest frame inserted with group by vehicle_id.
• Max(id) or Max(info_datetime) query will not give the accurate result.

Answer 1

SELECT id, vehicle_id FROM table_name as a WHERE info_datetime = 
(SELECT MAX(info_datetime) FROM table_name as b WHERE a.vehicle_id = b.vehicle_id)
GROUP BY vehicle_id

Answer 2

Your attempt is almost there, but you need to join by id as well:

select a.id,a.vehicle_id,a.info_datetime 
from table_name a 
join (
    select vehicle_id, max(info_datetime) as maxdt from table_name group by vehicle_id
) as b on a.info_datetime = b.maxdt and a.vehicle_id = b.vehicle_id

Another way to do it is to filter with a correlated subquery:

select a.*
from table_name a
where a.info_datetime = (
    select max(b.info_datetime) from table_name b where b.vehicle_id = a.vehicle_id 
)

Answer 3

• Finally got the solution for above.

SELECT id, vehicle_id, info_datetime
FROM table_name
WHERE id in (
    select max(m2.id) from table_name m2 group by m2.vehicle_id)
ORDER BY vehicle_id asc,info_datetime DESC

• It will take approx 2 to 3 seconds to execute in around 25 lac records.