DSXchange

Hello,

I am using 11.5 PX. When I try this IF THEN clause in Transformer stage:

if columnA <> '' then 'RT' else if columnB <> '' then 'RT' else if columnC <> '' then 'RT' else if columnD <> '' then 'RT' else if columnE <> '' then 'RC' else if columnF <> '' then 'RF' else ''

Unfortunately, this always returns 'RT' and never evaluates to other conditions.

Thanks for support.

Juan

Out of curiosity, are you trying to check for "empty" columns and if so, what exactly does empty equate to in whatever you are checking? I'm wondering if you are looking for an empty string when they are (or can be) NULL instead... which are not equivalent.

Hi Chulett,
thanks for reply

i am checking only non null string from multiple columns (A,B,C,..). If it is not null then evaluate to constant value

don't know if this answers to your question...

Sort of. Make sure you understand that NULL and an empty string are not the same thing. Have you tried using either the IsNull or IsNotNull functions as appropriate?

Sure. tried IsNotNull then got same unexpected output.

how to evaluate multiple if---then in Transformer? maybe my syntax is wrong

i appreciate any help

Thanks.

It depends on the priority of the conditions. If a condition you know to be true is not being evaluated, it's because a lower priority condition is true first.

Break out your logic into single statements, and do a final logic check based on the priority of the true conditions. Or, as I've found helpful in complex business requirements, consider setting a flag instead of setting the string value. Then check the flags for the final string you want to appear.

EDIT: Actually, the first problem could be that you're using negative logic. Instead of <> empty string, set flags for a column being empty. Negative logic is always tricky to get right.

Hi Franklin, thanks for this new approach. i will it a try

Ssome things...
- if your data is not exactly matching, it will not be as expected. You may need to trim first, then check vs empty string.
- if your data type is char, not varchar, it will not be possible to ever be empty string even after a trim.
- if the first columns trigger RC, the latter conditions won't do anything due to else. Else only happens when the conditions are false. That is, to get RF, you need multiple false returns on the early conditions.

It looks like you could simplify this logic. Maybe not, it depends on what you really have and what you really want.

Consider putting 'a' if col a is true, 'b' if col b is true ... etc to debug your logic. Multiple conditions giving the same result is harder to debug. You can put it back once you fix it.

I suspect one of the fields columnA/B/C/D is CHAR. If it is, then your test will always return 'RT' because a CHAR field is fixed length and can never be empty. It will always be padded with $APT_PAD_CHAR (usually spaces, or Hex zeroes (0x0).

hi ,
as Franklin and UCDI suggested, i broke into single statement using stage variables. then i created a new column with conditions.
This works and is much simpler

Thanks to all