topic Re: Tmap Joins in Talend Studio

Tmap Joins

Daemon_demon — Fri, 15 Nov 2024 22:17:28 GMT

Hello,

In one of my situation, the data in my source table is mixture of null and not-null values. I have to do following operations:

If the ip column is null , pass it as is to output say TABLE A
If the ip column is non-null , inner join it with lookup table and send it to the output Table A.
Get the rejects from inner-join performed in step 2 and send it to other table , Table B .

I can perform 2/3 operations using a tMap, is it possible to to perform all 3 ops?

Please not, i am trying to avoid additional components like tfilter or bufferInput

Thanks!

Re: Tmap Joins

Anonymous — Thu, 08 Dec 2022 08:45:27 GMT

Hello,

Could you please elaborate your case with an example with input and expected output values?

Best regards

Sabrina

Re: Tmap Joins

jlolling — Fri, 09 Dec 2022 10:15:40 GMT

You need 2 tMap components. In the first tMap component you split the incoming flow into 2 output flows. One for null values and the 2. output flow for not null values. The second flow have to be the input for the 2. tMap and here you can do the inner join.

You cannot do everything in one tMap!

Re: Tmap Joins

Daemon_demon — Tue, 13 Dec 2022 11:27:13 GMT

Hi,

Thanks for providing the answers!

For @Xiaodi Shi 's question for input i had some think like

And Reference table like :

I am joining on the 'VAL' column of both tables and trying to get two outputs.

One table with PK 1,2 and 3 -> This table should contain all the matching values plus the values for which we have null as input from source such as PK=3.

Other table with PK 4 -> This table indicates such values that are present in source bit not in reference table,

@Jan Lolling . I am currently doing this by using inner join :

Create three output tables.
For table 1 will have all the valid values that are matching with the reference table.
Table 2 will be on the inner join's reject records (by enabling the option on catch lookup rejects option ) additionally filtered with the condition where input column is null.
Table3 will be on the inner join's reject records (by enabling the option on catch lookup rejects option ) additionally filtered with the condition where input column is not null.

I am storing the table 1 and 2 in tHashoutput which will be later merged and stored.

Please let me know if there are any other optimal ways to achieve this tasks.

Thanks!!

Re: Tmap Joins

jlolling — Tue, 13 Dec 2022 12:04:44 GMT

I think my former answer works here.