topic Data flow down in Talend in Talend Studio

Data flow down in Talend

Anonymous — Wed, 28 Jun 2017 19:19:03 GMT

Hi,

I am new to Talend, working on a project where i need to flow the data down from previous transactions.

Please help

Here's an example

Input

ID, Rev, Col1, Col2, Col3

1, 1, X1, NULL, X4

1, 2, NULL, NULL, NULL

1, 3, X2, X3, NULL

1, 4, NULL, NULL, NULL

Output

ID, Rev, Col1, Col2, Col3

1, 1, X1, NULL, X4

1, 2, X1, NUL, X4

1, 3, X2, X3, X4

1, 4, X2, X3, X4

I am struggling to hold the previous row values. Also, this data is for particular id, values flow within the id rows only.

Please help

Re: Data flow down in Talend

Vilas4muppidi — Wed, 28 Jun 2017 19:55:48 GMT

The output you mentioned is what you are expecting

Re: Data flow down in Talend

Anonymous — Wed, 28 Jun 2017 20:00:17 GMT

Yes, that is what i am expecting..
If id is same and column has no value , the last entry's value should flow down

Re: Data flow down in Talend

Anonymous — Thu, 29 Jun 2017 03:28:06 GMT

You can do this in tMap or in a tJavaRow.

If the number of columns is not too many, a tJavaRow may be faster.

You will assign the current not null value to a globalMap variable. Then pull the value from globalMap variable and replace the column value if the column value is null. If the column value is not null, then maybe you want to overwrite the globalMap variable.

Look at the help for the tJavaRow