topic Re: How to use SQL Lag Function concept in talend in Talend Studio

How to use SQL Lag Function concept in talend

RAJ6 — Wed, 01 Nov 2017 08:04:42 GMT

Hi Talend Folks,

How to use Sql LAG function concept in talend.
The Lag function gives the previous column values based on ordering.
please check below link you will get clear idea for Sql LAG function
http://www.c-sharpcorner.com/UploadFile/f82e9a/lag-and-lead-functions-in-sql-server/
How to do this requirement in tmap component or some other component?

Re: How to use SQL Lag Function concept in talend

Anonymous — Wed, 01 Nov 2017 08:46:55 GMT

Hi there,

This sort of thing can be done very easily in a tJavaFlex component, as follows.

The tFixedFlowInput generates rows with a single Integer column:

Add a new column to the output schema of th tJavaFlex component for the LAG value:

And the the following code will output the previous (LAG) value, before setting it to the current value of newColumn, which will be available when the next row is processed:

Regards,

Chris

Re: How to use SQL Lag Function concept in talend

Anonymous — Fri, 17 Apr 2020 17:03:26 GMT

use sort before that to get lead functionality..