Unmatched Rows in Look up stage

[ajith]

I want to know how to get only the unmatched rows in a particular look up. Is it possible to do this with look up stage alone.

I was trying to achieve this by specifying the look up condition. But It does not allow me to use reference link columns. I cannot change the link ordering as that is disabled.

I want to avoid using one more stage here, is it possible to do in a look up stage?

Thanks in advance,
Ajith

[ThilSe]

Hi Ajith

One way is to set "When Match not found" to 'Reject' and catch the records in the reject link. But in my opinion, the reject stream should be used only for error or reject records processing.

The "lookup condition" is evaluated 'before' doing the actual lookup which is used to specify whether the lookup has to be performed for that record or not.

Thanks and Regards
Senthil

[ray.wurlod]

If what you want to do is identify those rows in the reference Data Set that were not touched by the Lookup stage, without using any more stages, the answer is no.

With more stages, the answer is yes. You need to capture the distinct lookup keys that came from the stream input, downstream of the Lookup stage (Copy and Remove Duplicates stages for example) then perform any kind of difference or outer join between that Data Set and the reference Data Set.

[ajith]

Thank you Ray,

I decided to add one more filter stage to sort this out.

Senthil,

As you said, I feel it is improper to use reject link, I dint even check this option out. Thank you too.


Thanks,
Ajith