topic Expression to compare with first value in QlikView

Expression to compare with first value

rfigueroa — Fri, 04 Nov 2011 01:44:53 GMT

Hi,

In the example attached, I would like to add a fourth column so their value will be the current Quantity minus the Quantity value from the first Purchase for the same Product.

For example for product A, Fx will be Qty - 10 which is the value from the first purchase:

productID dtPurchase Quantity Fx

A 01/01/2000 10 0

A 01/02/2000 9 1

A 01/03/2000 8 2

I know that's very simple for you guys...hope can you help me.

Thanks in advance.

Cheers.

Roberto

Expression to compare with first value

matt_crowther — Fri, 04 Nov 2011 10:06:27 GMT

Roberto,

Try top(Quantity) as you'r expression - it works for me in your example file.

You can of course use top(total Quantity) to take the very first record.

Hope that helps,

Matt - Visual Analytics Ltd

Expression to compare with first value

rfigueroa — Fri, 04 Nov 2011 15:43:57 GMT

Thank you Matt, but seems the results change when we change the order. I need an expressions that returns always the first Quantity value from the first purchase for each product.

Robert.

Re: Expression to compare with first value

johnw — Fri, 04 Nov 2011 22:35:24 GMT

This seems to be working, though I didn't check it particularly carefully:

Quantity-firstsortedvalue(total <productID> Quantity,dtPurchase)

Re: Expression to compare with first value

rfigueroa — Sat, 05 Nov 2011 00:12:03 GMT

works perfect! thank you John.