declare @workhourperday int
set @workhourperday = 8

select p.salary, em.lname, em.fname, em.mname, 
case when sum(datediff(ss,datelogin+' '+timein, datelogin+' '+timeout))/(3600*@workhourperday) <> (select workingdays from working_day)
     THEN salary/(sum(datediff(ss,datelogin+' '+timein, datelogin+' '+timeout))/(3600*@workhourperday)) else salary/(select workingdays from working_day) end as salary_per_day
FROM
DTR d inner join emp_mas em
on d.empid = em.empid
inner join emp_det ed
on em.empid = ed.empid
inner join position p
on p.posid = ed.empid
WHERE
datepart(month, datelogin) = 6 and datepart(year, datelogin) = datepart(year, getdate())