Get the latest month rows within a year? - aggregate-functions

Question

I want to get the latest data from a table in ABAP.
Here an example from the table ckmlcr:
MANDT
KALNR
BDATJ
POPER
UNTPER
CURTP
PEINH
VPRSV
STPRS
PVPRS
WAERS
...
100
000100000000
2020
007
000
10
1
S
1.00
0.00
JPY
...
100
000100000000
2020
007
000
30
1
S
1.00
0.00
JPY
...
100
000100000000
2020
007
000
31
1
S
1.00
0.00
JPY
...
100
000100000000
2020
008
000
10
1
S
1.00
0.00
JPY
...
100
000100000000
2020
008
000
30
1
S
1.00
0.00
JPY
...
100
000100000000
2020
008
000
31
1
S
1.00
0.00
JPY
...
100
000199999999
2020
007
000
10
1
S
20.00
0.00
EUR
...
100
000199999999
2020
007
000
30
1
S
25.00
0.00
EUR
...
100
000199999999
2020
007
000
31
1
S
20.00
0.00
EUR
...
I want to get the latest data for each KALNR so this would mean my output table should have following values:
MANDT
KALNR
BDATJ
POPER
UNTPER
CURTP
PEINH
VPRSV
STPRS
PVPRS
WAERS
...
100
000100000000
2020
008
000
10
1
S
1.00
0.00
JPY
...
100
000100000000
2020
008
000
30
1
S
1.00
0.00
JPY
...
100
000100000000
2020
008
000
31
1
S
1.00
0.00
JPY
...
100
000199999999
2020
007
000
10
1
S
20.00
0.00
EUR
...
100
000199999999
2020
007
000
30
1
S
25.00
0.00
EUR
...
100
000199999999
2020
007
000
31
1
S
20.00
0.00
EUR
...
My program should have as selection the year
PARAMETERS: bdatj TYPE ckmlcr-bdatj DEFAULT sy-datum+0(4) OBLIGATORY.
and should uses the highest period (POPER) for each cost estimate number (KALNR).
What is the easiest way to achieve this? Due to a lot of data it would be nice to directly get the filtered data within the SQL select on the table.
This would be the SQL statement without any modifications to get the latest data.
SELECT * FROM ckmlcr INTO TABLE #DATA(ckmlcr_single)
WHERE kalnr = #<ckmlcr_line>-kalnr
AND bdatj = #bdatj.

Answer 1

Learn how to use subqueries
SELECT kalnr, bdatj, poper, untper, curtp, peinh, vprsv, stprs, pvprs, waers
FROM ckmlcr AS cr
INTO TABLE #DATA(ckmlcr_single)
WHERE bdatj = #bdatj
AND poper = ( SELECT MAX( poper ) from ckmlcr WHERE kalnr = cr~kalnr AND bdatj = cr~bdatj ).
P.S. Habituate yourself to put select fields explicitly instead of asterisk, it will serve a good job in future.

Answer 2

What worked for me is:
SELECT * FROM ckmlcr INTO TABLE #DATA(ckmlcr_single)
WHERE kalnr = #<ckmlcr_line>-kalnr
AND bdatj = #bdaj
AND poper = ( SELECT MAX( poper ) from ckmlcr
WHERE kalnr = #kalnr
AND bdatj = 2022 ).
This solution only works for a single kalnr not as requested above for the whole table.
Thus means my program currently looking like this:
" get single kalnr
SELECT DISTINCT kalnr FROM ckmlcr INTO TABLE #DATA(data_ckmlcr)
WHERE bdatj = #bdatj
ORDER BY kalnr.
LOOP AT data_ckmlcr ASSIGNING FIELD-SYMBOL(<ckmlcr_line>).
" get the latest data from this kalnr
SELECT * FROM ckmlcr INTO TABLE #DATA(ckmlcr_single)
WHERE kalnr = #<ckmlcr_line>-kalnr
AND bdatj = #bdatj
AND poper = ( SELECT MAX( poper ) from ckmlcr
WHERE kalnr = #<ckmlcr_line>-kalnr
AND bdatj = #bdatj ).
[...]
ENDLOOP.
Due to a select in a loop that is not quite performant...