Query to aggregate totals between dates - sql

Question

I have data of the following format:
Date Value
08/28 100
09/01 1
09/01 5
09/10 2
I would like my output to be:
Date Value
08/28 100
08/29 100
08/30 100
08/31 100
09/01 106
09/02 106
.
.
.
09/10 108
I'm just getting started with SQL, so any help would be appreciated. What I have right now is below, but that's not really close to what I seek:
SELECT Date, COUNT(DISTINCT(Service)) AS Value
FROM [Directory]
WHERE Date <= #myDate
GROUP BY Date ORDER BY Date

Answer 1

First, you can use a sub query to get the aggregate values
SELECT Date, (SELECT SUM(Value) FROM Directory d WHERE d.Date <= Directory.Date)
FROM [Directory]
WHERE Date <= #myDate
ORDER BY Date
Which would give you something that looks like this:
Date Value
08/28 100
09/01 101
09/01 106
09/10 108
Then you can add a Date table as sgeddes suggested. This article explains if fairly well: http://michaelmorley.name/how-to/create-date-dimension-table-in-sql-server
Then you can modify your query like so
SELECT DateTable.Date, (SELECT SUM(Value) FROM Directory d WHERE d.Date <= Directory.Date)
FROM [Directory] LEFT OUTER JOIN DateTable on Directory.Date = DateTable.Date
WHERE DateTable.Date <= #myDate
ORDER BY DateTable.Date
To get the data format you're looking for.

Answer 2

Based on sgeddes suggestion:
SELECT a.Date, COUNT(DISTINCT(d.Service)) AS Value
FROM [Directory] d
LEFT OUTER JOIN [Date Table] a on d.Date = a.Date
WHERE Date <= #myDate
GROUP BY Date
ORDER BY Date

Answer 3

Use following script in sqlserver :
BEGIN
--If exist then drop temp tables
DROP TABLE #YOURTABLE;
DROP TABLE #TEST1;
DECLARE #MINDATE DATETIME;
DECLARE #MAXDATE DATETIME;
CREATE TABLE #YOURTABLE(
CDATE DATE,
VALUE INT
);
INSERT INTO #YOURTABLE VALUES ('08/28/2014',100),('09/01/2014',1),('09/01/2014',5),('09/10/2014',100);
--select start date and end date from your table
SELECT #MINDATE=MIN(CDATE),#MAXDATE=MAX(CDATE) FROM #YOURTABLE;
CREATE TABLE #TEST1(
CDATE DATE,
VALUE INT
);
;WITH CALENDAR
AS (
SELECT #MINDATE CDATE
UNION ALL
SELECT CDATE + 1
FROM CALENDAR
WHERE CDATE + 1 <= #MAXDATE
)
-- insert all dates with 0 value in temp table
INSERT INTO #TEST1 SELECT CDATE,0 FROM CALENDAR;
--delete dates which are already there in your table
DELETE FROM #TEST1 WHERE CDATE IN (SELECT CDATE FROM #YOURTABLE)
-- insert all dates with values from your table to temporary table which holds dates which are not in your table
INSERT INTO #TEST1 SELECT * FROM #YOURTABLE;
SELECT T1.CDATE,(SELECT SUM(VALUE) FROM #TEST1 T2 WHERE T2.CDATE<=T1.CDATE) FROM #TEST1 T1
END