topic Re: if exists(field, 'value') then ... endif. Need a minimalistic working example. in App Development

if exists(field, 'value') then ... endif. Need a minimalistic working example.

NikVladi — Mon, 07 Oct 2024 23:18:04 GMT

I came across a construction in QV on the Internet:

if exists(field, 'value') then
...
endif

I applied it. There are no errors. But I don't see that it works at all. Could you give me a minimalistic working example. I know that exists is usually used when loading a table, but this is a different case.

Re: if exists(field, 'value') then ... endif. Need a minimalistic working example.

Vegar — Tue, 08 Oct 2024 05:12:46 GMT

I believe exists() only works in load statements. Try FieldIndex instead.

Fruits:
Load * inline [
Fruit
Apple
Banana
Grape];

if FieldIndex('Fruit','Banana') 
   trace Banana exists;
endif

if FieldIndex('Fruit', 'Orange') then
   trace Orange exists;
endif

if not FieldIndex('Fruit', 'Orange') then
   trace Orange does not exists;
endif

Re: if exists(field, 'value') then ... endif. Need a minimalistic working example.

NikVladi — Tue, 08 Oct 2024 23:35:43 GMT

Thanks. It works. But you know what else works? Exists instead of FieldIndex. It's really funny.

Fruits:
Load * inline [
Fruit
Apple
Banana
Grape];

if Exists('Fruit','Banana') 
   trace Banana exists;
endif

if Exists('Fruit', 'Orange') then
   trace Orange exists;
endif

if not Exists('Fruit', 'Orange') then
   trace Orange does not exists;
endif

Re: if exists(field, 'value') then ... endif. Need a minimalistic working example.

Vegar — Wed, 09 Oct 2024 05:50:02 GMT

That is funny.🤯

I will try your syntax. I've assumed the first parameter to be a field reference and not a string, but I notice you use stringsforr all parameters.

Me: Exists(Fruit,'Banana')

You: Exists('Fruit','Banana')

If this is true, then it will my learning of the day. Thanks!

Re: if exists(field, 'value') then ... endif. Need a minimalistic working example.

NikVladi — Wed, 09 Oct 2024 05:58:08 GMT

Yeah, I decided to try it and it worked. You know, I think it's going to be a revelation for QlikTech in their entire history as well.