DSXchange

Input_Lnk

Parent_code child_code CHILD_SK PARENT_SK
00.1 1
ABC.20 ABC 2
ABC.20 CDE.20 3
ABC.20 EFG.20 4
BDE.20 ABC.20 5

I am using stage varaible to get parent_sk like below

in stage varaible i said

Input_Link.child_code StageVar


In Transformer to populate PARENT_SK i said

IF (Input_Lnk.Parent_code= StageVar) THEN Input_Lnk.CHILD_SK ELSE 1

i am getting all parent_sk as 1

i should have get

Parent_code child_code CHILD_SK PARENT_SK
00.1 1 1
ABC.20 ABC 2 5
ABC.20 CDE.20 3 5
ABC.20 EFG.20 4 5
BDE.20 ABC.20 5 5

Format your post using Code tags so it's clear what's happening. It's too difficult to fathom with the way you've presented your information.

i want to update parent_sk as below based upon join from parent_code with child_code:

I am reading this as follows:
IF (Input_Lnk.Parent_code= Input_Link.child_code) THEN Input_Lnk.CHILD_SK ELSE 1

Agree so what should it be

Based on the way I understood your question and input data, no Parent Code is matching with Child code, so it goes to ELSE part of your code and prints 1 which is correct.