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Anonymous
Not applicable

How to select BLANKS or <NULL> values

Hi,

I have created a tablebox which containes values like this:

fielda fieldb fieldc fieldd fielde

1 2 A B C
3 4 D E F
5 G H I
6 7 J K

etc, etc

In fieldb and fieldc there a lot of records with no value. What I want is that the user can select those BLANKS so that only the recors appears which do not have a vlaue in column fieldb or fieldc.

I have read this in other threads:

quote

Do you have a NullAsValue in your script ?

or check your NullInterpreter variable ?

unquote.

However nothing works. Can anybody help me with this?

1 Solution

Accepted Solutions
Miguel_Angel_Baeyens

What you say is right: you cannot select a null value because it doesn't exist.

But, if I understood your question right, if you create a flag field to mark all records in the table that don't have any value will allow you to add this new field to your tablebox so you will be able now to select those records flagged (those who have one or more null fields).

Regards.

View solution in original post

15 Replies
Not applicable
Author

Isnull : to select blanks

NOT isnull : to select where not blank

Is this along the right lines.........

Anonymous
Not applicable
Author

I'm sorry I'm not sure what you mean by that . I don't think that NOT isnull will solve my problem, because I want to see everything that ISNULL.

jedgson
Creator
Creator

using

Nul AsValue *;


In your script should work

Anonymous
Not applicable
Author

I've tried something like this, but the empty one still do not shows up. Not in Customer Number nor in Not Available.

ODBC

CONNECT TO something;

[Something]:

set

LOAD

CUSTNMBR as [Custumor Number]
IF("DOCNUMBR" <> '<NULL>', "CUSTNMBR", '000000000000') as [Not Available]; NullValue='<NULL>';
NULLASVALUE *;





jedgson
Creator
Creator

Put the NullAsValue at the beginning of the script

Anonymous
Not applicable
Author

Hi it still doesn't work. My very first line in the script is:

NULLASVALUE *;

Then I test DOCNUMBR with the following if statement.

IF

(IsNull("DOCNUMBR"), 'Not Available', ' ') as [Not Available];





The result is in case that the DOCNUMBR contains a value, that [Not Available] will have the value ' ' as expected.
When DOCNUMBR doesn't has a value, the result is that [Not available] has a <NULL> value. I'm expecting there the text "Not Available".

When I select in the tablebox the '' value in the [Not Available] column all rows are selected with exeption of the rows with a <NULL> value as expected.
When I try to select the <NULL> value, nothing happens at all. It seems that QlikView can't make that selection.

So, I'm still confused. Any idea's?

Miguel_Angel_Baeyens

Hello,

You can flag those records and then select only them. RangeNullCount returns the number of null values in the passed expressions. You only have to pass on the function all fields, creating a new field in the LOAD statement:

RangeNullCount(fielda, fieldb, fieldc, fieldd, fieldd) AS NullCount


Then you can use any where statement, conditional expression or set analysis to select only those records where NullCount is greater than 0.

Hope that helps!

jonathandienst
Partner - Champion III
Partner - Champion III

I don't think NullAsValue helps the user to select null values. Essentially you cannot select null values using a click select. You can transform the null values as you have tried, although I would probably use something like this during loading

If(IsNull(DOCNUMBR), 'Not Available', 'Available') as [IsAvailable],

Alternatively, you can use Advanced Search to find the nulls. If you select a list box and start typing, the search dialog comes up. Normally, the search string starts with ** (wildcards), but if you select a list box and type =, you can enter an advanced search expression, for example:

=IsNull(DOCNUMBR) or =Len(DOCNUMBR)=0 (these two are equivalent, in theory, but I find the second more reliable)

That will select all entries in the list box that have (or are linked to other table records that have) a null value of DOCNUMBR.

If that is too complicated for your users, you can save the advances serach in a bookmark.

Jonathan

Logic will get you from a to b. Imagination will take you everywhere. - A Einstein
Not applicable
Author

Hi,

i think nullasvalue or isnull solutions doesn't work for your case.Because your values are blank values.

You must try a solution like this.

if(length(FIELD)<2,'Blanks',FIELD)