topic Re: Cumulative sum in script in QlikView

Cumulative sum in script

Tue, 30 May 2017 13:06:20 GMT

Hi Qlikers,

i have a problem simple to understand but difficult to solve for me.

I have a Warehouse movements table with the movements of one year back (MOVEMENTS_1YB).

I need to make a cumulative sum of QTA_MOV_1YB grouped by CAUSAL_MOV_1YB,DATE_MOV_1YB and ITEM and ordered by DATE_MOV_1YB.

My goal is produce a field within the script called CUM_QTA_MOV_1YB.

I've attached the script that produce an error ('INVALID EXPRESSION') now.

MOVEMENTS_1YB:

LOAD

ITEM,

QTA_MOV_1YB,

DATE_MOV_1YB,

CAUSAL_MOV_1YB

RESIDENT WAREHOUSE_MOVEMENTS

WHERE DATE_MOV_1YB>=ADDMONTHS(DATE(TODAY()),-$(ROLLING_PERIOD));

CUMULATIVE_SUM:

LOAD

ITEM,

DATE_MOV_1YB,

CAUSAL_MOV_1YB,

SUM(QTA_MOV_1YB)+PEEK(CUM_QTA_MOV_1YB) AS CUM_QTA_MOV_1YB

RESIDENT MOVEMENTS_1YB

GROUP BY CAUSAL_MOV_1YB,DATE_MOV_1YB,ITEM;

DROP TABLE MOVEMENTS_1YB;

Anybody can help me?

Thanks in advance.

Re: Cumulative sum in script

vinieme12 — Tue, 30 May 2017 13:13:28 GMT

do you really need peek()??

just this would do

CUMULATIVE_SUM:

LOAD

ITEM,

DATE_MOV_1YB,

CAUSAL_MOV_1YB,

SUM(QTA_MOV_1YB) AS CUM_QTA_MOV_1YB

RESIDENT MOVEMENTS_1YB

GROUP BY CAUSAL_MOV_1YB,DATE_MOV_1YB,ITEM;

DROP TABLE MOVEMENTS_1YB;

Re: Cumulative sum in script

Oleg_Troyansky — Tue, 30 May 2017 13:23:22 GMT

Hi Michele,

in fact, you need a combination of peek() and previous(). With previous(), you can compare the current values of Causal, Date, and Item with the previous values and only if they are the same, then you'd accumulate the values, otherwise you'd start from zero.

Something like this:

IF(Previous(Causal)=Causal and Previous(Date)=Date and Previous(Item) = Item, peek('Cumulative_Qty') + Qty, Qty) as Cumulative_Qty

Notice that Previous() doesn't require single quote around the field name, while Peek() does. There is a reason for using Previous() in your comparison and Peek() in the calculation. I'm describing the process with a lot of detail in my book QlikView Your Business, also using this technique for the Inventory Analysis - check it out!

cheers,

Oleg Troyansky

Re: Cumulative sum in script

ahaahaaha — Tue, 30 May 2017 13:25:53 GMT

Hi Michele,

Try

CUMULATIVE_SUM:

LOAD

ITEM,

DATE_MOV_1YB,

CAUSAL_MOV_1YB,

RangeSum(QTA_MOV_1YB, Peek('CUM_QTA_MOV_1YB')) as CUM_QTA_MOV_1YB

RESIDENT MOVEMENTS_1YB

GROUP BY CAUSAL_MOV_1YB,DATE_MOV_1YB,ITEM;

DROP TABLE MOVEMENTS_1YB;

Regards,

Andrey

Re: Cumulative sum in script

Oleg_Troyansky — Tue, 30 May 2017 13:26:49 GMT

One more thought... I just noticed your GROUP BY clause. If you just need to aggregate all transactions by these three fields, then you don't need to use Peek() and Previous(). I assumed from your description that you need to know the CUMULATIVE value at the time of each individual transaction (that's common in Inventory Analysis). If you need that, then you don't need to use GROUP BY - just reload the data, sorted by your 3 key fields and a timestamp, and use Peek() and Previous() for the CUMULATIVE calculation.

Cheers,

Oleg Troyansky

Re: Cumulative sum in script

Oleg_Troyansky — Tue, 30 May 2017 13:28:36 GMT

Folks,

Peek() won't work in combination with GROUP BY - you can only use one of the two, but not both techniques at the same time.

Re: Cumulative sum in script

Tue, 30 May 2017 14:21:29 GMT

Unfortunately it doesn't work fine.

An error message like "AGGREGATION EXPRESSIONS REQUIRED BY GROUP BY CLAUSE" is appeared.

Re: Cumulative sum in script

Tue, 30 May 2017 14:25:39 GMT

I've followed your suggestion using

"IF(Previous(Causal)=Causal and Previous(Date)=Date and Previous(Item) = Item, peek('Cumulative_Qty') + Qty, Qty) as Cumulative_Qty" without GROUP BY and the script works fine but the Cumulative_Qty field is empty.

which is the other method?

Re: Cumulative sum in script

Oleg_Troyansky — Tue, 30 May 2017 14:29:18 GMT

That's exactly my point (read above) - you can use either GROUP BY with sum(), or Peek and Previous, but without Group By.

The GROUP BY clause requires using aggregation functions like SUM().

In order to follow the technique that I suggested, remove the GROUP BY clause.

Re: Cumulative sum in script

Tue, 30 May 2017 14:31:05 GMT

I'm sorry but there isn't an accumulation with this method.

Re: Cumulative sum in script

ahaahaaha — Tue, 30 May 2017 14:58:31 GMT

First, you can create a new table with the required grouping, and then reload it, accumulating data in the field

RangeSum (QTA_MOV_1YB, Peek ( 'CUM_QTA_MOV_1YB')), как CUM_QTA_MOV_1YB

Re: Cumulative sum in script

Wed, 31 May 2017 09:34:21 GMT

Thank you Oleg, I'm confident that i'm near the solution but there are some problems yet.

This is my script with the peek and previous method:

WAREHOUSE_MOVEMENTS:

LOAD

ITEM,

DATE_MOV,

MONTH_MOV,

QTY_MOV,

CAUSAL_MOV

RESIDENT MOV_MAG

ORDER BY ITEM ASC,DATE_MOV ASC,CAUSAL_MOV ASC;

DROP TABLE MOV_MAG;

CUMULATIVE_SUM:

LOAD

ITEM,

IF((

Previous(CAUSAL_MOV) = CAUSAL_MOV and

Previous(DATE_MOV) = DATE_MOV and

Previous(ITEM) = ITEM

(peek('CUM_QTA_MOV_1YB')+QTY_MOV),

QTY_MOV) AS CUM_QTA_MOV_1YB

RESIDENT WAREHOUSE_MOVEMENTS;

Unfortunately the result isn't so good yet.

and so on.

I think that the key field ITEM isn't enough to linking tables.

I show you what i want to have like result.

.................................................................................................................................... and so on.

I've changed the key with a composite key but it hasn't a good idea.

Can you tell me what there is wrong??

Thank you in advance!!! I think i will buy your book.

Re: Cumulative sum in script

Oleg_Troyansky — Wed, 31 May 2017 14:16:52 GMT

Hi Michele,

A few comments:

1. Based on your desired output, it looks like you want to accumulate quantities just by Items, not by Item, Date, and Causal.

So, in this case, you should only compare Item with the Previous(Item).

2. Based on our desired output, you need to add the cumulative "running total" in the same table with the movements, not in a separate table by ITEM - that would produce wrong results.

So, I think your script should look like this:

WAREHOUSE_MOVEMENTS_TEMP:

LOAD

ITEM,

DATE_MOV,

MONTH_MOV,

QTY_MOV,

CAUSAL_MOV

RESIDENT

MOV_MAG

ORDER BY

ITEM ASC,DATE_MOV ASC,CAUSAL_MOV ASC;

DROP TABLE MOV_MAG;

WAREHOUSE_MOVEMENTS:

LOAD

ITEM,

DATE_MOV,

MONTH_MOV,

QTY_MOV,

IF((

Previous(ITEM) = ITEM

RangeSum(peek('CUM_QTA_MOV_1YB') , QTY_MOV),

QTY_MOV) AS CUM_QTA_MOV_1YB

RESIDENT

WAREHOUSE_MOVEMENTS_TEMP

ORDER BY

ITEM,

DATE_MOV,

CAUSAL_MOV

;

DROP TABLE WAREHOUSE_MOVEMENTS_TEMP;

I also replaced a simple addition ( the plus sign) with a RangeSum, to protect it against an accidental NULL value...

Now you better buy my book 🙂

cheers,

Oleg Troyansky

Re: Cumulative sum in script

Thu, 01 Jun 2017 14:14:56 GMT

Well, now everything is perfect!!!!

I surf in internet to buy your book of course!!

I want to increase my development ability!!!

Re: Cumulative sum in script

Oleg_Troyansky — Thu, 01 Jun 2017 14:36:38 GMT

Hi Michele,

glad I could help. You can find the book here:

QlikView Your Business

cheers,

Oleg Troyansky