Section Access in OBIEE 12c - weblogic12c

Question

I'm trying to Implement Section Access in OBIEE 12c . I referred a Blog and followed the steps to Implement Section Access . But the End Result is not as Expected .
Blog Link : http://bisimplified.blogspot.com/2014/06/obiee-11g-datarow-level-security.html
First I created "User_1" and Assigned that user to "BI Consumer" Application Role.
I want to display only certain data to the "User_1".
Created Initialization Block .
This is the SQL Statement I used to define the Initialization Block ( Data Source ) :
select pc.category_name from dim_category ft , product_categories pc where ft.category_id=pc.category_id and lower(ft.username) = lower(':USER') .
(Screenshot of Initialization Block created )
I assigned 'default' (String) to Default Initializer and Check in the " Row-Wise Initialization" and "Use Caching" ( Initialization Block (Block we are working on ) -> Edit Variable Target -> New ( Variable )) .
(Screenshot of Session Variable created)
Else , an error prompted at the assigning the Section variable to the Application Role / User , if the Default Initializer is left empty .
(Screenshot of Error Message if the Default Initializer left empty and try to assign that Section variable to the Application Role / User ).
Is there anything to be done with Session Variable ?
After that I assign this Session Variable to the "BI Consumer " Application Role .
(Screenshot of Assigning Session Variable to "BI Consumer" Application Role )
I request to give suggestion on " Implementing Section Access " in OBIEE 12c or if there is anything you like to Add in the above steps please correct me.

Answer 1

Consolidated answer for general knowledge: "Section Access" is a misnomer. The intent is "row-level security".
The problem mentioned with the query above stems primarily from the usage of ':USER' which most likely is "weblogic" and who owns/has no data for that query.
The query must be validated using a user account which actually brings back data.
Secondly, since the query is set to row-wise initialization it must bring back value pairs representing the variable name and an actual value.
Section_Variable | CategoryA
Section_Variable | CategoryB
etc
So the SQL must pull
select
'Section_Variable',
ft.category_name
from
.....