example_manual_agg.sql

declare @eva table -- entity value attribute 
(
	id int identity, -- we could use date here either
	type nvarchar(100),
	value nvarchar(100),
	student_identifier int
)

insert @eva (type, value, student_identifier) 
select 'studentid', '1', 3
union all 
select 'studentid', '2', 3
union all 
select 'startdate', CONVERT(NVARCHAR(100), getdate()), 3
union all 
select 'startdate', CONVERT(NVARCHAR(100), ( select getdate()-1)), 3 

select
	ev.student_identifier,
	MAX ( CASE WHEN TYPE ='startdate' then value else null end ) as start_date,
	MAX ( CASE WHEN TYPE ='studentid' then value else null end ) as student_id
from @eva AS ev 
WHERE EXISTS 
(
	select *
	from 
	(
		select max(e.id) AS id , e.type
		from @eva as e 	
		group by e.type
	) AS m
	WHERE 
		m.id = ev.id 
)
GROUP BY 
	ev.student_identifier