Question

I have a query:

SELECT   [outer].*,
         (total_pain_patients / NULLIF ((SELECT Sum(total_pain_patients)
             FROM   [topplansperprovider]
             WHERE  [outer].[INDEX_IMSID] = [INDEX_IMSID]
             AND plan_rank BETWEEN 1 AND 10), 0)) * 100 AS PercentOf,
         pm.*,
         percentof * pm.score
FROM     [topplansperprovider] AS [outer]
left JOIN [payer Mapping] pm
on lower([outer].Plan_Name_OR_Payment_Type)=lower(pm.[ims payer name])
WHERE    INDEX_IMSID = '1753841'
ORDER BY 6 ASC

My problem is with selecting this:

percentof * pm.score

Since percentof is the alias of a derived column, I don’t know how to use it in other columns.

1. How do I select percentof * pm.score?
2. If that is too difficult, how can I just add percentof as a permanent column to my table?

Answer 1

You cannot use an alias like that, you will have to wrap the query in another select:

select x.*, x.percentof*x.pm.score newvalue
from
(
    SELECT   [outer].*,
             (total_pain_patients / NULLIF ((SELECT Sum(total_pain_patients)
                                             FROM   [topplansperprovider]
                                             WHERE  [outer].[INDEX_IMSID] = [INDEX_IMSID]
                                                    AND plan_rank BETWEEN 1 AND 10), 0)) * 100 PercentOf,
             pm.*
    FROM     [topplansperprovider] AS [outer]
    left JOIN [payer Mapping] pm
        on lower([outer].Plan_Name_OR_Payment_Type)=lower(pm.[ims payer name])
) x
WHERE    x.INDEX_IMSID = '1753841'
ORDER BY 6 ASC

The column alias that you are calculating percentof is not available for use in another column, unless is it used in a sub-query.