topic Re: Assigning previous row id to next row in Talend Studio

Assigning previous row id to next row

Prakhar1 — Sat, 16 Nov 2024 04:46:08 GMT

Hi,

I have a table like

item_id,item_name

1,a

1,b

1,c

2,x

2,y

2,z

Now, I want the output to be like:

surr_key, item_id,item_name, parent_id

1,1,a,-1

2,1,b,1

3,1,c,2

4,2,x,-1

5,2,y,4

6,2,z,5

Here, surr_key is auto_increment and parent_id is the surr_key of precious row for the same item_id.

a is the first item for item_id=1 thus it will be -1 and same with x.

Can anyone help how to achieve it ?

Re: Assigning previous row id to next row

Anonymous — Thu, 05 Sep 2019 12:10:31 GMT

This post answers a slightly different question, but you can use the method to do what you want. Essentially you are looking at the functionality which means that tMap variables are actioned in order from top to bottom and they preserve their values between rows.

https://community.talend.com/t5/How-Tos-and-Best-Practices/Compare-row-value-against-a-value-from-the-previous-row/m-p/133710#M595

Re: Assigning previous row id to next row

Prakhar1 — Fri, 06 Sep 2019 07:25:47 GMT

how to do this with integer values, as the compareignorecase accepts string values only

Re: Assigning previous row id to next row

Anonymous — Fri, 06 Sep 2019 11:59:43 GMT

You can use compareTo() for Integers or == for primitive type ints