Question

I have a query whose code looks like this:

SELECT DocumentID, ComplexSubquery1 ... ComplexSubquery5
FROM   Document
WHERE  ...

ComplexSubquery are all numerical fields that are calculated using, duh, complex subqueries.

I would like to use this query as a subquery to a query that generates a summary like the following one:

   Field          DocumentCount           Total
     1                 dc1                 s1
     2                 dc2                 s2
     3                 dc3                 s3
     4                 dc4                 s4
     5                 dc5                 s5

Where:

dc<n> = SUM(CASE WHEN ComplexSubquery<n> > 0 THEN 1                  END)
s <n> = SUM(CASE WHEN Field = n              THEN ComplexSubquery<n> END)

How could I do that in SQL Server?

---

NOTE: I know I could avoid the problem by discarding the original query and using unions:

SELECT '1' AS TypeID,
       SUM(CASE WHEN ComplexSubquery1 > 0 THEN 1 END) AS DocumentCount
       SUM(ComplexSubquery1)                          AS Total
FROM   (SELECT DocumentID, BLARGH ... AS ComplexSubquery1) T
UNION ALL
SELECT '2' AS TypeID,
       SUM(CASE WHEN ComplexSubquery2 > 0 THEN 1 END) AS DocumentCount
       SUM(ComplexSubquery2)                          AS Total
FROM   (SELECT DocumentID, BLARGH ... AS ComplexSubquery2) T
UNION ALL
...

But I want to avoid this route, because redundant code makes my eyes bleed. (Besides, there is a real possibility that the number of complex subqueries grow in the future.)

Answer 1

WITH Document(DocumentID, Field) As
(
SELECT 1, 1 union all
SELECT 2, 1 union all
SELECT 3, 2 union all
SELECT 4, 3 union all
SELECT 5, 4 union all
SELECT 6, 5 union all
SELECT 7, 5
), CTE AS
(
SELECT DocumentID, 
       Field, 
       (select 10) As ComplexSubquery1,  
       (select 20) as ComplexSubquery2,
       (select 30) As ComplexSubquery3,  
       (select 40) as ComplexSubquery4,
       (select 50) as ComplexSubquery5
FROM   Document
)
SELECT Field, 
       SUM(CASE WHEN RIGHT(Query,1) = Field AND QueryValue  > 1 THEN 1 END ) AS DocumentCount,
       SUM(CASE WHEN RIGHT(Query,1) = Field THEN QueryValue END ) AS Total
FROM CTE
UNPIVOT  (QueryValue FOR Query IN 
      (ComplexSubquery1, ComplexSubquery2, ComplexSubquery3, 
       ComplexSubquery4, ComplexSubquery5)
)AS unpvt
GROUP BY Field

Returns

Field       DocumentCount Total
----------- ------------- -----------
1           2             20
2           1             20
3           1             30
4           1             40
5           2             100