Add missing datas at a table

[Schalhas]

I have a table with missing periods. 200703 and 200709-200710

MONTHSUM:
GRP_FIELD	PERIOD	MONTH_END_VALUE
4248/21	200701	1040
4248/21	200702	895
4248/21	200704	750
4248/21	200705	740
4248/21	200706	730
4248/21	200707	710
4248/21	200708	550
4248/21	200711	435
4248/21	200712	315

The result should be a table with all periods and for missing values - add the value of the prior period or prior periods.

GRP_FIELD	PERIOD	MONTH_END_VALUE
4248/21	200701	1040
4248/21	200702	895
4248/21	200703	895
4248/21	200704	750
4248/21	200705	740
4248/21	200706	730
4248/21	200707	710
4248/21	200708	550
4248/21	200709	550
4248/21	200710	550
4248/21	200711	435
4248/21	200712	315

First step was to create a table with all periods:

BU_PERIOD:
BUPERIOD
200701
200702
200703
200704
200705
200706
200707
200708
200709
200710
200711
200712

2^nd Step to connect the two tables:

TEMP:

LOAD Distinct

GRP_FIELD,

PERIOD

Resident MONTHSUM;

Join(MONTHSUM) LOAD

BUPERIOD as PERIOD

Resident BU_PERIOD;

Drop Table TEMP;

At this step I still miss the periods.

3^rd Step: Add missing values in empty fields

RESULT:

NoConcatenate

LOAD *,

if(isnull(MONTH_END_VALUE),peek(MONTH_END_VALUE ), MONTH_END_VALUE) as MS_ENDWERT_KUM_1

Resident MONTHSUM order by GRP_FIELD, PERIOD asc;

Drop Table MONTHSUM;