topic Re: How to test if a field has value or is null (not linked)? in App Development

How to test if a field has value or is null (not linked)?

Alessio — Mon, 10 Dec 2018 09:32:35 GMT

Hi,

I have this problem.

I have table A with field 'CodiceArticolo' and table B with fields 'CodiceArticolo' and 'Articolo'.

In a visualization of table type (see image), I have do check if 'Articolo' has no value. I tried to use IsNull function but I noticed that it works only if record in table B exists, while if a record linked to that CodiceArticolo doesn't exist in table B (and so I have no value for 'Articolo') IsNull function returns a kind of null value.

How can I do? Does other specific function exist?

Thanks

Re: How to test if a field has value or is null (not linked)?

Gabriel — Mon, 10 Dec 2018 09:57:01 GMT

Hi,

Try IF(ISNULL(Articolo) OR LEN(Articolo) =0,'T','F')

Re: How to test if a field has value or is null (not linked)?

Anil_Babu_Samineni — Mon, 10 Dec 2018 10:05:15 GMT

FIFO : Try this?

IF(Len(Articolo)>0, 'F', 'T')

Re: How to test if a field has value or is null (not linked)?

Alessio — Mon, 10 Dec 2018 10:10:37 GMT

Thanks but it doesn't work... none of 2 suggestions

Re: How to test if a field has value or is null (not linked)?

Anil_Babu_Samineni — Mon, 10 Dec 2018 10:13:57 GMT

Should work, For my case with sample it is working

Table1:
LOAD * Inline [
Name
A
B
C
D
];

Table2:
LOAD * Inline [
Name, Name1
A,
B, Sample
C, Sample1
D,
];

How is your data looks like?

Re: How to test if a field has value or is null (not linked)?

Gabriel — Mon, 10 Dec 2018 10:19:11 GMT

Hi,

In the script use script below before table A & B

Map_NullValues:

MAPPING LOAD

NULL() AS [MapFrom],

'<Unknown>' AS [MapTo]

AUTOGENERATE (0);

MAP * USING Map_NullValues;

Then in the UI you can then rewrite your expression IF(FieldName = '<Unknown>', 'T','F')

Re: How to test if a field has value or is null (not linked)?

Alessio — Mon, 10 Dec 2018 10:25:04 GMT

My data look like this:

Table1:
LOAD * Inline [
Name
A
B
C
D
];

Table2:
LOAD * Inline [
Name, Name1
A,
B, Sample
];

Re: How to test if a field has value or is null (not linked)?

micheledenardi — Mon, 10 Dec 2018 10:53:13 GMT

MapValues:
Mapping
LOAD 
	Name,
	Name1
Inline [
Name, Name1
A,
B, Sample
];


Table1:
load
	Name,
	Name1,
	if(isnull(Name1) or trim(Name1)='','True','False') as Flag_IsNull;
LOAD 
	Name,
 	ApplyMap('MapValues',Name,null()) as Name1
Inline [
Name
A
B
C
D
];

And the result is: