Role of Only() here

[#1]

Hi All,

I want to show data of year 2018 in metric. I have used following expression & it works correctly but could anyone can explain me role of only here. I can understand why only used here. Please explain in details.

Year(Only({<YR={2018}>}[Exp Date]))

Thanks in Adv

[Anil_Babu_Samineni]

Only Function will get only 2018 Data

Year([Exp Date]) is give all years like your data Assume if you have data 2010 - 2020. It will get 2018 of Exp Dates only

[#3]

I have checked articles says if multiple values returns Only() function will return NULL(). But I tried following expression but it works. I don't know exactly how it works.

Year(Only({<YR={2018,2019,2020}>}[Exp Date]))

[rahulpawarb]

Hello Narendra,

Only() function will fetch a value if there is one and only one possible result from the aggregated data. Example given by you, searching for the only [Exp Date] where the YR = 2018 will return NULL if more than one [Exp Date] has a YR equal to 2018 else [Exp Date].

Hope this will be helpful.

P.S.: Use Only() when you want a NULL result if there are multiple possible values in the sample data.

Regards!

Rahul

[Anil_Babu_Samineni]

This case, will fetch Dates only for 2018, 2019, 2020

How to use - Only()

[jonathandienst]

Rahul has this exactly correct. The other answers are a little less accurate.

Also see these articles:

Use Aggregation Functions!

It’s all Aggregations

[muthukumar77]

Refer this,

Only - chart function ‒ QlikView

[beck_bakytbek]

Hi Narenda,

look at this:

https://community.qlik.com/docs/DOC-8146#comment-58605

i hope that helps

beck

[#9]

But I tried YR = 2018 which gives 3 lines of output as data contains 3 lines for 2018. It returning 3 lines.