Adding a further group into a recursive CTE - sql-server

Question

Referring back to this SO post
If there is a Grouping category "Category" which, for simplicity's sake, can be either X or Y - is it a trivial matter amending this script so that it will add in the missing dates for each of the categories ?
I assume the category will need adding into the CTE?
In other words if I have the following initial table:
...how do I get to the following:
Will upload my attempt shortly
I've called the initial table #x. I'm hoping to adapt a recursive CTE query like the following to include the field Category:
DECLARE #MinDate DATETIME;
SET #MinDate = (SELECT Min(DATE) FROM #x)
DECLARE #MaxDate DATETIME;
SET #MaxDate = (SELECT Max(DATE) FROM #x)
;WITH times AS
(
SELECT #MinDate dt , 1 depth
UNION ALL
SELECT
DATEADD(d, depth, #MinDate) dt
, 1 + depth as depth
FROM times
WHERE DATEADD(d, depth, #MinDate) <= #MaxDate
)
SELECT
*
FROM
TIMES t
LEFT OUTER JOIN #X x
ON
t.dt = x.Date
Ok - I've tied including a CROSS JOIN but it expands things incorrectly:
SELECT DISTINCT Category INTO #Cat FROM #x
DECLARE #MinDate DATETIME;
SET #MinDate = (SELECT Min(DATE) FROM #x)
DECLARE #MaxDate DATETIME;
SET #MaxDate = (SELECT Max(DATE) FROM #x)
;WITH times AS
(
SELECT
Category
, #MinDate dt
, 1 depth
FROM #Cat
UNION ALL
SELECT
c.Category
, DATEADD(d, depth, #MinDate) dt
, 1 + depth as depth
FROM
times t
CROSS JOIN #Cat c
--ON c.Category IS NOT NULL
WHERE DATEADD(d, depth, #MinDate) <= #MaxDate
)
SELECT
*
FROM
TIMES
This seems to have worked ok:
SELECT DISTINCT Category INTO #Cat FROM #x
DECLARE #MinDate DATETIME;
SET #MinDate = (SELECT Min(DATE) FROM #x)
DECLARE #MaxDate DATETIME;
SET #MaxDate = (SELECT Max(DATE) FROM #x)
;WITH times AS
(
SELECT
Category
, #MinDate dt
, 1 depth
FROM #Cat
UNION ALL
SELECT
Category
, DATEADD(d, depth, #MinDate) dt
, 1 + depth as depth
FROM
times t
WHERE DATEADD(d, depth, #MinDate) <= #MaxDate
)
SELECT
*
FROM
TIMES

Answer 1

Here is a solution without a calendar table (which is a must in production). You might have date range in variables, or you might go for min() and max() from the_table.
EDIT: shorter version incorporating categories into date range generation
declare #startdate datetime = '2012-1-1'
declare #enddate datetime = '2012-1-5'
; with dates([date], category) as (
select distinct #startdate, category
from the_table
union all
select dateadd (day, 1, [date]), category
from dates
where [date] < #enddate
)
select dates.date,
dates.category,
isnull(the_table.amount, 0) Amount
from dates
left join the_table
on dates.date = the_table.date
and dates.category = the_table.category
order by dates.category, dates.date
option (maxrecursion 0)
There is live test # Sql Fiddle.
New Sql Fiddle.

Answer 2

Something like this should do the trick:
declare #curDate datetime, #maxDate datetime
declare #count tinyint
select #curDate = convert(datetime, '20120101', 112), #maxDate = getdate()
select #count = 0
while #curDate < #maxDate
begin
select #count = count(1) from tablename where Category = 'X' and convert(varchar(8), Date, 112) = convert(varchar(8), #curDate, 112)
if #count > 0
begin
insert into tablename
select 'X', #curDate, 0
end
select #curDate = dateadd(dd, 1, #curDate)
end