Analytics Software

Hi I am a beginner to the ODI 12C

I am trying  to get two latest comments done on product for a given product id. and load them into a target.

I have a source table something like

SR_NO              product            comments                   LAST_UPDATED_TS

   1                     car                     good                       2015/05/15 8:30:25

   1                     car                     average                  2015/05/15 10:30:25

   2                     jeep                    super                     2015/05/15 11:30:25

   1                     car                      bad                       2015/05/15 11:30:25

   2                     jeep                    horrible                  2015/05/15 9:30:25

   2                     jeep                    excellent               2015/05/15 12:30:25

I want a target table  based on their last updated time stamp like(Two latest Comments)         

SR_NO               Comment1               Comment2

1                             bad                      average  

2                            excellent                  super 

I used the below logic to get the records in SQL developer but in ODI 12C I am not able to achieve this by mapping one source to target table by applying analytical functions to the columns in target table. Can anyone help me to solve this 

SELECT * FROM (

SELECT SR_NO, Comment1, LAG(Comment1,1,NULL) OVER ( PARTITION BY SR_NO ORDER BY LAST_UPDATED_TS ASC) Comment2,

ROW_NUMBER() OVER (PARTITION BY SR_NO ORDER BY LAST_UPDATED_TS DESC ) RN

FROM Source_table

) M

WHERE RN =1

;