Question

I have a table that looks like this:

Month   | Year  | Rate
2011    | Jan   | 50
2011    | Jun   | 55 
2011    | Nov   | 53 

Since this table I want use for financial calculation I need output in below format:

Month   | Year  | Rate
2011    | Jan   | 50
2011    | Feb   | 50
2011    | Mar   | 50
2011    | Apr   | 50
2011    | May   | 50
2011    | Jun   | 55
2011    | Jul   | 55
2011    | Aug   | 55
2011    | Sep   | 55
2011    | Oct   | 55
2011    | Nov   | 53
2011    | Dec   | 53

Any help, please

Answer 1

The gist of the statement goes like this

• Use an in memory table to add ID's to month names.
• Combine this table with your original rates table to generate each month with a either an existing rate or NULL.
• SELECT from this FullYearRates table and retrieve the non existing rates using a subselect on this table.

SQL Script

;WITH months ([ID], [Month]) AS (
  SELECT 1, 'Jan'
  UNION ALL SELECT 2, 'Feb'
  UNION ALL SELECT 3, 'Mar'
  UNION ALL SELECT 4, 'Apr'
  UNION ALL SELECT 5, 'May'
  UNION ALL SELECT 6, 'Jun'
  UNION ALL SELECT 7, 'Jul'
  UNION ALL SELECT 8, 'Aug'
  UNION ALL SELECT 9, 'Sep'
  UNION ALL SELECT 10, 'Oct'
  UNION ALL SELECT 11, 'Nov'
  UNION ALL SELECT 12, 'Dec'
)  
, Rates ([Year], [Month], [Rate]) AS (
  SELECT 2011, 'Jan', 50
  UNION ALL SELECT 2011, 'Jun', 55 
  UNION ALL SELECT 2011, 'Nov', 53 
)
, FullYear ([Year], [Month], [ID]) AS (
  SELECT  DISTINCT r.[Year], m.[Month], m.Id
  FROM    Rates r
          CROSS APPLY months m
)
, FullYearRates ([Year], [Month], [Rate], [ID]) AS (
  SELECT  fy.[Year], fy.[Month], r.[Rate], fy.ID
  FROM    FullYear fy
          LEFT OUTER JOIN Rates r ON r.[Month] = fy.[Month] AND r.[Year] = fy.[Year]
)
SELECT  r1.[Year]
        , r1.[Month]
        , [Rate] = (
            SELECT  Rate 
            FROM    FullYearRates fr
                    INNER JOIN (
                      SELECT  ID = MAX(ID) 
                      FROM    FullYearRates 
                      WHERE   ID <= r1.ID 
                              AND Rate IS NOT NULL
                    ) fm ON fm.ID = fr.ID                              
          )                    
FROM    FullYearRates r1