Unable to view data of Analytical View having calculated attribute/measure

Hi,

I have few Analytical View deployed in my test system. i am able to see the data of few analytical view by executing select statement (with group by clause) using studio.

Example: SELECT CAST(SUM(COL1 as DOUBLE) ) as COL1 , CAST(COL2 as NVARCHAR) as COL2 FROM _SYS_BI.<ANALYTICAL_VIEW> GROUP BY COL1

the same SQL query is throwing me error for the Analytical View containing calculated Attribute or calculated measure.

Please help to understand the SQL syntax to get the data.

Thanks

Hemant