topic Re: [resolved] How to create derived columns in Talend Studio

[resolved] How to create derived columns

Anonymous — Sat, 16 Nov 2024 13:49:42 GMT

Are there components for creating derived columns (additional columns in the data flow derived from other source columns)?
This is typically done at the start of dataflow, right AFTER the database input compoment.
Typical examples are for:
Data Conversion of a column to Unicode, but keeping the original column also
Data conversion from a string date to a data, but keeping the original column also
Data conversion from a date to a string, but keeping the original column also
Performing Date Math on a date column, and then storing results to another "derived" column in the data flow.
Performing string manipulation on a column, and then storing results to another "derived" column in the data flow.

Re: [resolved] How to create derived columns

Anonymous — Thu, 13 Aug 2009 03:25:20 GMT

Hello guy
First, extract the records from source file/database, then do the following transaction and finally output the result to target file/database.

Data Conversion of a column to Unicode, but keeping the original column also

You can convert a column to unicode in tJava or create a routine to do it.

Data conversion from a string date to a data, but keeping the original column also
Data conversion from a date to a string, but keeping the original column also
Performing Date Math on a date column, and then storing results to another "derived" column in the data flow.

Talend provide a class called TalendDate which can be used to format a date to a string, parse a string to a date, add date etc...In a word, you do any manipulation/conversion on date with this class.

Performing string manipulation on a column, and then storing results to another "derived" column in the data flow.

Yes, you can do fiter/merge/cut manipulation on string on tJava/tjavaRow/tMap components, etc..
Best regards

shong

Re: [resolved] How to create derived columns

Anonymous — Fri, 14 Aug 2009 18:32:27 GMT

Hello guy
First, extract the records from source file/database, then do the following transaction and finally output the result to target file/database.

Data Conversion of a column to Unicode, but keeping the original column also

You can convert a column to unicode in tJava or create a routine to do it.

Data conversion from a string date to a data, but keeping the original column also
Data conversion from a date to a string, but keeping the original column also
Performing Date Math on a date column, and then storing results to another "derived" column in the data flow.

Talend provide a class called TalendDate which can be used to format a date to a string, parse a string to a date, add date etc...In a word, you do any manipulation/conversion on date with this class.

Performing string manipulation on a column, and then storing results to another "derived" column in the data flow.

Yes, you can do fiter/merge/cut manipulation on string on tJava/tjavaRow/tMap components, etc..
Best regards

shong

Looks like I can do all type conversions, and derived (computed) columns, all within tMap. Pretty impressive - with SSIS that would have taken (albeit easy) 2 additional transformation components.
I wish the doc on tMap were better, or there was a detailed extensive document dedicated to it with numerous examples.
Thanks!
Dave