SQL - display selective output that is not sequenced last in a multiple occurrence - sql

Question

I have a table like below
OP OP_var SPS SPS_sq
1010 01 KEB_x 01
1010 01 KEK_x 02
1010 02 KEH_c 01
1010 02 KEK_y 02
1010 02 KEB_d 03
1020 01 KEK_f 01
1020 01 KEE_g 02
The OP column has variance (OP_var) and within it is a group of SPS. SPS_sq is the sequencing of these SPS lines within the OP+OP_var.
I would like to display KEK% where the KEK%'s SPS_sq is not last (meaning, the KEK% is either first or anywhere in the middle of the sequence number of the OP and OP_var as long as it is not last.
The output should look like this :
OP OP_var SPS SPS_sq
1010 02 KEK_y 02
1020 01 KEK_f 01
ignore all KEK% that is SPS_sq last within the OP+OP_var.

Answer 1

I assume you're looking for a random row per (op, op_var) combination. The random row has to have an SPS like 'KEK%', and it cannot have the same SPS as the last row. (That implies it cannot be the last row itself.)
This example uses window functions, which are available in SQL Server, Oracle, PostGRES. It uses a SQL Server specific way (newid()) to create a random order.
select *
from (
select row_number() over (
partition by yt1.OP, yt1.OP_var
order by newid()) as rn2 -- Random order
, yt1.*
from dbo.YourTable yt1
join (
select row_number() over (
partition by OP, OP_var
order by SPS_sq desc) as rn
, *
from YourTable
) as last_row
on yt1.OP = last_row.OP
and yt1.OP_var = last_row.OP_var
and last_row.rn = 1 -- Highest SPS_sq
where yt1.SPS <> last_row.SPS
and yt1.SPS like 'KEK%'
) SubQueryALias
where rn2 = 1 -- Random KEK row that doesn't share SPS with last row
Example at SQL Fiddle.

Answer 2

If you want all kek where kek is not at the max sps_sq for (op, op_var)
select * from Table1 t
where t.sps like 'KEK%'
and not exists
(select null from Table1 t1
inner join (select MAX(t2.sps_sq) as maxsps_sq, t2.op, t2.op_var
from Table1 t2
GROUP BY t2.op, t2.op_var) as getmax
on t1.op = getmax.op and t1.op_var = getmax.op_var
and t1.sps_sq = getmax.maxsps_sq
where t1.op = t.op and t1.op_var = t.op_var and t1.sps = t.sps and t.sps_sq = t1.sps_sq
);
SqlFiddle
Caution :
As Andomar's noticed, this will take all the kek% for an [op, op_var] which don't have the last sps_sq number.