Question

I have folowing MYsql Query And Trying to right outer join but unable to understan how to do this

here is query plase any one help

select lp_des.lpname,today.cnt_veh_tdy,todate.cnt_veh_tdate
from
(select distinct registration.lpcode,loadingpoint.lpname 
from registration,loadingpoint
where registration.lpcode=loadingpoint.lpcode) lp_des,
(select lpcode,count(vehicleno) cnt_veh_tdate
from registration
where registration.companycode='01'
group by lpcode) todate,
(
select lpcode,count(vehicleno) cnt_veh_tdy
from registration
where registration.companycode='01'
and registration.date=(select max(date) from registration)
group by lpcode) today
right outer join today on lp_des.lpcode = today.lpcode
right outer join todate on lp_des.lpcode = todate.lpcode

I want to make right outer join on this part

where lp_des.lpcode=todate.lpcode
and   lp_des.lpcode=today.lpcode

Please help and Thanks in advance

Answer 1

You asked for this:

select 
  lp_des.lpname,
  today.cnt_veh_tdy,
  todate.cnt_veh_tdate
from
  (select distinct 
    r.lpcode,
    l.lpname 
  from 
    registration r
    inner join loadingpoint l on l.lpcode = r.lpcode) lp_des
  right join
    (select 
      r.lpcode,
      count(r.vehicleno) cnt_veh_tdate
    from 
      registration r
    where 
      r.companycode='01'
    group by 
      lpcode) todate on todate.lpcode = lp_des.lpcode
  right join
    (select 
      r.lpcode,
      count(r.vehicleno) cnt_veh_tdy
    from 
      registration r
    where 
      r.companycode = '01'
      and registration.date = (select max(date) from registration)
    group by 
      r.lpcode) today on today.lpcode = lp_des.lpcode

But I think you mean this:

select
  r.lpcode,
  l.lpname,
  count(r.vehicleno) cnt_veh_tdate,
  count(case when r.date = md.date then r.vehicleno else null end) cnt_veh_tdy
from
  registration r
  inner join (select max(rm.date) maxdate from registration rm) md
  left join loadingpoint l on l.lpcode = r.lpcode
where
  r.companycode = '01'
group by 
  r.lpcode

and maybe even this:

select
  r.lpcode,
  l.lpname,
  count(r.vehicleno) cnt_veh_tdate,
  count(case when r.date = date() then r.vehicleno else null end) cnt_veh_tdy
from
  registration r
  left join loadingpoint l on l.lpcode = r.lpcode
where
  r.companycode = '01'
group by 
  r.lpcode

If I read it correctly, you want a query that returns the number of vehicles for company 1 assigned to a loading point, overall as well as for today only. And you also want that count for vehicles that do not have loading point assigned yet.
Though it would help if you would have added this description. It will help the ones answering your question, but it will also help you writing the right query in the first place.