Tsql union of sub queries that each require an ORDER BY clause

Question

Hi I apologize if the answer for this is somewhere else. I looked around and I could not see a simple solution. I have a query that I would like to run. I don't care about the order of the union set, only that the inner queries return the correct data which is the "Largest Areas".

(SELECT TOP 5 * FROM [geo].[Areas] WHERE CountryID = @CountryID AND (TypeID = 'City')
ORDER BY [ShapeArea] DESC) as BiggestCities
    UNION ALL
(SELECT TOP 5 * FROM [geo].[Areas] WHERE CountryID =  @CountryID AND (TypeID = 'National park')
ORDER BY [ShapeArea] DESC) as BiggestParks

But T-sql won't let me have ORDER BY on the sub-queries, only on the whole Union... Help appreciated! I would really prefer not to have to create temporary tables or anything like that.

Answer 1

Try this

SELECT * 
  FROM (SELECT TOP 5 * 
          FROM [geo].[Areas] 
         WHERE CountryID = @CountryID 
           AND (TypeID = 'City')
      ORDER BY [ShapeArea] DESC) as BiggestCities
UNION ALL
SELECT * 
  FROM (SELECT TOP 5 * 
          FROM [geo].[Areas] 
         WHERE CountryID =  @CountryID 
           AND (TypeID = 'National park')
      ORDER BY [ShapeArea] DESC) as BiggestParks

Answer 2

SELECT t.* /* Excluding RowNum */
  FROM (SELECT *, ROW_NUMBER() OVER (PARTITION BY TypeID ORDER BY [ShapeArea] DESC) as RowNum
          FROM [geo].[Areas]
          WHERE CountryID = @CountryID 
            AND TypeID IN ('City', 'National park')
       ) t
  WHERE t.RowNum <= 5