topic SV:calculate fieldvalue based on previous record, only field value first record is known in QlikView

calculate fieldvalue based on previous record, only field value first record is known

Fri, 22 Apr 2011 14:34:00 GMT

Simplified example:

I'm trying to calculate a fieldvalue in every row of a table.The calculation of the value is based on the previous record where only the first record is known. The formula looks like this: 6 * previous(fieldvalue).

Only the value of the first record is known. For example the Calculatedfield value of record 4 is based on the previous calculatedfield value of record 3 which is unknown.

RowID	Calculatedfield
1	2
2
3
4
5
6

I tried some do while loops but I can't get it to work. Any suggestions are very welcome!

SV:calculate fieldvalue based on previous record, only field value first record is known

ToniKautto — Fri, 22 Apr 2011 15:33:00 GMT

You shoul be able to solve that operation by using Peek() during load.

T1:
LOAD * Inline [
F1, F2
1, 4
2, 0
3, 0
];

T2:
LOAD
F1 as F3,
if(RowNo()=1, F2, Peek(F4) * 6) as F4
RESIDENT T1;

SV:calculate fieldvalue based on previous record, only field value first record is known

Fri, 22 Apr 2011 17:29:34 GMT

Thanks Toni, exactly what I was looking for. Good to know that QV peek function looks at the previous modified record and not at the 'original' table record.