Join stage: Need to retain the column key from both tables

[pdntsap]

Hello,

I have a join stage joining data from Table A and Table B based on join key Column A. Is there a way by which Column A from both Table A and Table B can be retained at the output of the Join stage?

Thanks.

[ray.wurlod]

Yes. Make an additional column in Table B that is a copy of the key and map that to the output.

[pdntsap]

That was quick, Ray.

My inputs are flat (sequential) files and not tables as previously mentioned. Sorry about that. I used a Copy stage after the Sequential file stage to create an additional column that will be a copy of the key column but it looks like the same input column cannot be mapped to more than one output column in the Copy stage. I used a Transformer stage after the Sequential file stage and was able to create a copy of the key column. It seems to be fine but I need to some more testing and will update my post again.

Thanks again.

[BI-RMA]

Hi pdntsap,

I can't see why You are interested to see the content of the join Column A from table B when they are (by definition) identical (in inner and left outer joins). You can always map the key value to multiple output fields after the join by using a copy stage.

DataStage will , however, provide the key-columns from both tables when using full outer join mode (which makes a lot of sense).

[pdntsap]

Roland,

The join stage uses inner join and I need the key columns from both inputs for further processing downstream. Thanks for your suggestion of copy stage after the join stage. I believe copy stage might lead to better performance (in terms of processing time) than a transformer stage.