php - MySql Query with INNER JOIN, GROUP BY and Max -

i have 2 tables, 1 looks this:

id, datetime, user_id, location , status // rest not relevant 

and other looks this:

 id, lastname // rest not relevant 

now want entry of first table highest datetime per user_id , ask other table lastname of user_id. simple...

i tried way (whick looks promising false nontheless):

select w.datetime, w.user_id, w.status, e.lastname worktimes w inner join employees e  on w.user_id=e.id  right join (select max(datetime) datetime, user_id   worktimes    datetime>1467583200 , location='16'    group user_id   order datetime desc ) v on v.user_id=w.user_id group w.user_id  order e.nachname; 

could give me hint please? i'm stuck @ while , begin knots in brain... :(

you close, actually:

select w.datetime, w.user_id, w.status, e.lastname worktimes w inner join      employees e       on w.user_id = e.id left join      (select max(datetime) datetime, user_id       worktimes        datetime > 1467583200 , location = '16'        group user_id      ) ww      on ww.user_id = w.user_id , w.datetime = ww.datetime order e.nachname; 

notes:

• you need join on datetime value.
• the right join unnecessary. replaced left join, i'm not sure want either. might start inner join see if produces want.
• do not use order by in subqueries in circumstances.
• you not need group by in outer query