topic WHen does the Previous() used?? in QlikView

WHen does the Previous() used??

nikhilgarg — Tue, 23 Sep 2014 05:30:21 GMT

HEy,

I was going through Previous(). I tried to use it in Expression Tab but there no Previous() is defined. But when i used Previous in Load script then there it is defined.

Does that mean i can use Previous() only in Load script or while loading data ??

Please help and also tell me the scenario where it is used most often.

Thanks

Re: WHen does the Previous() used??

kushalthakral — Tue, 23 Sep 2014 05:40:00 GMT

Dear Nikhil

Previous and Peek are two variables which always used in script not in the expressions

as both these function refers to the table and u do not have table during expression

Previous is always used to refer last loaded data in the table

Regards

Kushal Thakral

Re: WHen does the Previous() used??

ashfaq_haseeb — Tue, 23 Sep 2014 05:40:31 GMT

Hi,

Check if this helps

Peek() vs Previous() – When to Use Each

regards

ASHFAQ

Re: WHen does the Previous() used??

jagan — Tue, 23 Sep 2014 06:16:14 GMT

Hi Nikhil,

Note: Previous() is a script function not the chart function.

Sometimes during loading we need the values of certain columns of previous row in current row, for this scenario the Previous() is useful. One best example is previous day sales, check below example

Date Sales

1/1/2014 100

1/2/2014 200

1/3/204 150

Suppose if you want Previous day sales like below

Date Sales Previous Day Sales

1/1/2014 100 -

1/2/2014 200 100

1/3/204 150 200

For above we will use Previous() like below

LOAD

Date,

Sales,

Previous(Sales) AS PreviousDaySales

FROM DataSource;

Hope this helps you.

Regards,

jagan.

Re: WHen does the Previous() used??

Siva_Sankar — Tue, 23 Sep 2014 06:36:39 GMT

Hi Nikhil,

Previous() function is not a chart function, it is a script function. If you want to achieve the functionality of previous() in chart expression then you can use above() function in expression. Find the attached document. will help you to use the previous() functionality in charts using above() function.