Hi Krishna,
As per the SAP, do not mix the SQL and CE Scripts.
Please check the below points in your side.
1. Please make sure that ARTICLE_LOOKUP& SHOP_FACTS tables should exists in your schema(ONLINEB1)
2. SELECT t1.ARTICLE_ID,t1.category,t2.shop_id,t2.amount_sold,t2.quantity_sold
FROM :sel1 AS t1
LEFT OUTER JOIN :sel2 AS t2
ON t1.article_id = t2.article_id ;
3. Add the "CATEGORY","AMOUNT_SOLD","QUANTITY_SOLD" to Output parameter(var_out)
Thanks
Basha