topic Re: IsNull() function in QlikView

IsNull() function

Mon, 08 Jun 2015 05:34:25 GMT

hi, can anybody tell me in simple words what is IsNull() and why and where is it used?

Re: IsNull() function

qlikmsg4u — Mon, 08 Jun 2015 05:38:53 GMT

FInd the needful info on this thread.

https://community.qlik.com/message/489669#489669

Re: IsNull() function

satishkurra — Mon, 08 Jun 2015 05:39:44 GMT

In qlikview, we can handle null values in source in 2 ways.

1. IsNull

2. Alt function

Example:

LOAD * Inline [

Product, Sales, Rate

A,100,1.2

B,200,1.3

C,300, ];

Reload the above script and create straight table with Product as dimension and expressions as

Sum(Sales*Rate)

You will observe only 2 records as 1 record has null value.

Solution1:

In chart properties, expressions tab, modify expression as

Sum(Sales * Alt(Rate,1)

Solution2:

In script window, write the script as

if(ISNULL(Rate),1,Rate) as Rate

We can handle null values in the above fashion.

Let me know if there is anything required.

Thanks

Satish

Re: IsNull() function

Gysbert_Wassenaar — Mon, 08 Jun 2015 05:40:08 GMT

You can find that information in the help file. Open Qlikview and press the F1 key.

IsNull(expr )

Returns -1 (true) if expr returns NULL, otherwise 0 (false).

Re: IsNull() function

Anonymous — Mon, 08 Jun 2015 05:45:56 GMT

In simple words, as you ask:

IsNull(Field) returns true (-1) if the value of the Field is null, and returns false (0) if the value of the Field is not null.

Re: IsNull() function

Mon, 08 Jun 2015 06:18:43 GMT

this is was not helpful at all..

Re: IsNull() function

Mon, 08 Jun 2015 06:19:18 GMT

not helpful...I cudnt understand the basic meaning

Re: IsNull() function

Mon, 08 Jun 2015 06:19:38 GMT

thanku ! very helpful indeed !

Re: IsNull() function

Peter_Cammaert — Mon, 08 Jun 2015 07:54:53 GMT

Do you understand the concept of "NULL"?

NULL is a special value used in database products to signify that a cell or field contains nothing, not even the empty string or 0. It can also mean uninitialised, meaning that this cell has never been used before.

true and false are names for values that are actually numerical. true is equal to -1, and false is equal to 0. In QlikView you can use them interchangeably: it doesn't matter which one you use.

IsNull() is used - amongst others - to check whether a field or a table cell actually contains a value that should get your attention. You may prefer to act on IsNull() = true to fill some field with a default value (e.g. 'UNKNOWN') when it contains nothing, or to throw away a row when the most important field is missing.

It would help if you could tell us what exactly isn't clear to you instead of the Good/Not Good qualification.

Peter

Re: IsNull() function

Mon, 08 Jun 2015 09:43:14 GMT

really sorry didn't meant that way..

n thanku for the explanation

Re: IsNull() function

Gabriel — Mon, 08 Jun 2015 11:18:07 GMT

Hi,

Please read this blog post by HIC for better understanding of NULL

Re: IsNull() function

Gysbert_Wassenaar — Mon, 08 Jun 2015 11:55:41 GMT

IsNull(expr) returns -1 (true) if expr returns NULL, otherwise 0 (false).

What part(s) of this sentence don't you understand?

Re: IsNull() function

ToniKautto — Mon, 08 Jun 2015 12:00:08 GMT

Please remember to mark correct and helpful answers, to show your gratitude for the effort that has been put in to answering your questions. It will also indicate if you are happy with the replies or if you require more input.

Re: IsNull() function

ashishpalkar — Tue, 18 Sep 2018 12:52:49 GMT

Hi Gysbert

How can we use following in Qlik?

,ISNULL(I.instrumentcusip,ISNULL(I.instrumentsedol,ISNULL(I.instrumentisin,I.instrumentticker))) AS [SECURITY ID]

thanks

Re: IsNull() function

Gysbert_Wassenaar — Tue, 18 Sep 2018 13:15:05 GMT

You can use it as text to fill some space. Put '//' in front of it and it can be used as a comment.

Isnull takes only one argument. So it you try to use it with two arguments your script will throw an error.

If you have a question then creating a new discussion for it is a better idea than digging up a discussion that's been dead and buried for three years.

Re: IsNull() function

jafari_ervin — Mon, 26 Nov 2018 04:11:03 GMT

qlikview help is very useful.

https://help.qlik.com/en-US/sense/November2018/Subsystems/Hub/Content/Sense_Hub/Scripting/NULLFunctions/IsNull.htm