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Transformer Null handling and reject link

Posted: Mon May 26, 2008 10:00 pm
by PrasannaLkashmiBurri
Hi,
I have tried the job regarding transformer null handling like to create a transfomer reject link,right click on on an output link and choose "convert to reject" but i didn't get the colums having null values in the reject link.Can any one tell how to get the colums having null values through reject link.

Thanks,
Prasanna Lakshmi.

Re: Transformer Null handling and reject link

Posted: Mon May 26, 2008 11:31 pm
by mithun.mg
PrasannaLkashmiBurri wrote:Hi,
I have tried the job regarding transformer null handling like to create a transfomer reject link,right click on on an output link and choose "convert to reject" but i didn't get the colums having null values in the reject link.Can any one tell how to get the colums having null values through reject link.

Thanks,
Prasanna Lakshmi.

Hello,

Please check the log in the data stage director ,If the records with NULL are getting dropped or not.If they are getting dropped then take care of NULL Handling in Transformer stage.

Posted: Mon May 26, 2008 11:34 pm
by ag_ram
This could have been best posted in Parallel Forum.
..choose "convert to reject" but i didn't get the colums having null values in the reject link..
I just checked with a Parallel Job with your the scenerio(If i properly understood your need) - Input dataset has null-valued columns, Output dataset has nonnull-valued columns but all Null values come from Input dataset should be sent to Reject dataset.

And I got the null values come from Input sent to Reject dataset.
Job Log wrote:APT_CombinedOperatorController,0: Field 'Col1' from input dataset '0' is NULL. Record sent to reject dataset.
Can you please elaborate this more, if i did not get properly.

Posted: Tue May 27, 2008 1:21 am
by PrasannaLkashmiBurri
Hai,
Actually transformer will drop the coloums having null values in the expression derivation.But i should get the coloums having null values when we right click on output link and choose "convert to Reject" option i should get null valued colums through reject link.Is it possible with the option "covert to reject".

Thanks,
Prasanna.

Posted: Tue May 27, 2008 1:59 am
by bkumar103
the reject link will cater only those records which is not processed by any other link. hence filter the records with proper validation( In this case not null validation) for the liks others than the reject link. Then check if the records flows into reject link.

Posted: Tue May 27, 2008 2:40 am
by ag_ram
PrasannaLkashmiBurri wrote:Hai,
Actually transformer will drop the coloums having null values in the expression derivation.But i should get the coloums having null values when we right click on output link and choose "convert to Reject" option i should get null valued colums through reject link.Is it possible with the option "covert to reject".
Parallel Job Developer's Guide in Page# 448 wrote:Handling Null Values in Input Columns:
If you use input columns in an output column expression, be aware that a null value in that input column will cause the row to be dropped or, if a reject link has been defined, rejected.
As per your scenerio, you should get rows which do have null values in any columns, in the Transformer Reject Link.

Posted: Tue May 27, 2008 3:23 am
by prasanna2883
Hi,

Use a Constraint IsNotNull(Column_name), and apply Null handling function NullToValue() for the columns which are getting dropped and you will be able to retrieve the records in reject link

Posted: Sat May 31, 2008 3:50 am
by ag_ram
prasanna2883 wrote:Hi,

Use a Constraint IsNotNull(Column_name), and apply Null handling function NullToValue() for the columns which are getting dropped and you will be able to retrieve the records in reject link
If the Stream Output Link of a Transformer Stage is converted to Reject Link using "Convert to Reject" option, that converted Reject Link does not have any appearance of Column Derivation box in the Transformer Stage, which is but used for capturing the records which are not output by any Stream Output Link and the records which are likely to be dropped.

Posted: Sat May 31, 2008 4:02 pm
by ray.wurlod
Or you could make an Otherwise/Log output link (from the Transformer stage) which will serve the same function but which does allow you to specify the record schema on it.