CODEWITHSUNDEEP
sqlsql-serversql-server-2008outer-join
Jey
Jey

Reputation: 37

SQL fill days for dates not found in Database

I'm getting data from my function as follows:

Date       |   Number
06-02-2012 |    2
06-05-2012 |    5
06-08-2012 |    5

If i want to include all dates that are not found in DB in the following matter how would i do it?:

Date       |   Number
06-02-2012 |    2
06-03-2012 |    0
06-04-2012 |    0
06-05-2012 |    5
06-06-2012 |    0
06-07-2012 |    0
06-08-2012 |    5

SELECT convert(varchar, MIN(DATEADD(wk, DATEDIFF(wk, 0, person.date), 0)), 1), Count(person.ID) 
FROM [dbo].[Person] person
WHERE (DATEDIFF(D, person.date, @dateFrom) <=0 AND DATEDIFF(D, person.date, @dateTo) >=0) 
GROUP BY DATEPART(WK, person.date)

Upvotes: 0

Views: 448

Answers (3)

Andr&#225;s Ott&#243;
Andr&#225;s Ott&#243;

Reputation: 7695

If you need just a small interval, you can try a function like this:

DECLARE @minDate date
DECLARE @maxDate date

SET @minDate = '2012-09-01'
SELECT @maxDate = CAST( CONVERT( CHAR(8), GetDate(), 112) AS DATETIME)


DECLARE @Numbers TABLE(
  Date date,
  Number int)

WHILE @minDate < @maxDate
BEGIN
INSERT INTO @Numbers
SELECT @minDate, 0
WHERE NOT EXISTS( SELECT Number FROM Numbers WHERE [Date] = @minDate )

SET @minDate = DATEADD(day, 1, @minDate)

END

SELECT n.[Date], ISNULL(n.Number, 0) 
FROM @Numbers n
UNION ALL
SELECT Numbers.[Date], ISNULL(Numbers.Number, 0) 
FROM Numbers 
ORDER BY [Date]

If you need more month and year, then I think the best way to make a prefilled permanent helper table with the dates what you need. And make only an easy join on them like it is posted in an other answer.

Upvotes: 0

Salman Arshad
Salman Arshad

Reputation: 272446

I recommend that you create a table of dates -- a one column table containing dates from, say 2000-01-01 to 2050-12-31. You can then use that table on the left hand side of a LEFT JOIN query like this:

SELECT date_table.date AS [Date], COUNT(your_table.primary_key) AS [Number]
FROM date_table
LEFT JOIN your_table ON date_table.date = your_table.date
WHERE date_table.date BETWEEN '2012-01-01' AND '2012-06-30'

Index the date table wisely and you'll end up with a very efficient query.

Upvotes: 0

podiluska
podiluska

Reputation: 51514

You would create a temporary table, or subquery, containing all the dates in your chosen range, and use a left join against your source data

Upvotes: 2

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