Question

This question is related to this SO post

Rather than using a recursive CTE how do I add in missing data (deemed missing via date) using a DimDates table?

I have the following two tables:

create table the_table 
(
  [Date] datetime,
  Category2 varchar(10),
  Amount INT
)
insert into the_table
values
( '01 jan 2012', 'xx', 10),
( '03 jan 2012', 'yy', 50)


create table DimDate 
(
  [Date] datetime
)
insert into DimDate
values
( '01 jan 2012'),
( '02 jan 2012'),
( '03 jan 2012'),
( '04 jan 2012')

These are the results I’m trying to get to. I’ve not bothered with a recursive CTE as I, wrongly assumed, it’d be loads easier using our warehouse DimDate table:

ok – i might have stumbled on a possible solution – please poke holes in the following if it’s wrong:

select

  coalesce(x.[Date], y.[Date]) AS Date ,
  coalesce(x.Category2, y.Category2) AS Category2 ,
  isnull(Amount,0) as Amount
from the_table x
full outer join 
(
select 
    d.Date
    , t.Category2
from 
        the_table t
        cross join DimDate d 
) y
    on
    x.Category2 = y.Category2
    and 
    x.Date = y.Date

this is what I’ve ended up with. A combination of the marked answer amd the cte from Aaron’s post:

;WITH 
    Dates_cte ([Date]) AS
            (
            SELECT [Date] = DayMarker 
            FROM WHData.dbo.vw_DimDate x
            WHERE
                    x.DayMarker >= (SELECT MIN([Date]) FROM #Data1 WHERE Period = 'Daily') AND
                    x.DayMarker <= GETDATE()
            )   
    ,Categories ([Operator], [Market], [Product], [Measure]) AS 
                ( 
                SELECT DISTINCT 
                        [Operator]
                        , [Market]
                        , [Product]
                        , [Measure] 
                FROM #Data1 
                WHERE [Period] = 'Daily'
                ) 
INSERT INTO #Data1 
    SELECT 
         c.[Operator]
        , c.[Market]
        , c.[Product]
        , [Period] = CONVERT(VARCHAR(100), 'Daily')
        , d.[Date]  
        , c.[Measure]   
        , 0 
    FROM Dates_cte d CROSS JOIN Categories c
    WHERE NOT EXISTS 
            ( 
            SELECT * 
            FROM #Data1 AS T 
            WHERE 
                    t.[Period] = 'Daily' AND
                    t.[Operator] = c.[Operator] AND 
                    t.[Market] = c.[Market] AND 
                    t.[Product] = c.[Product] AND 
                    t.[Measure] = c.[Measure] AND 
                    t.[Date] = d.[Date] 
            ) 

Answer 1

Use INSERT INTO ... SELECT FROM DimDate CROSS JOIN categories WHERE NOT EXISTS ....

Try this:

INSERT INTO the_table
([Date], Category2, Amount)
SELECT [Date], category2, 0
FROM DimDate
CROSS JOIN
(
    SELECT DISTINCT category2 FROM the_table
) AS categories
WHERE NOT EXISTS
(
    SELECT *
    FROM thetable AS T
    WHERE T.category2 = categories.Category2
    AND T.[Date] = DimDate.[Date]
)

See it working online: ideone

If you’re creating a data warehouse, I’d advise you to put the categories into a dimension table.