SQL Find missing date ranges

Question

I have a table that holds all the days/months of the year

E.G.

Day      Month
1         9
2         9
3         9
4         9
5         9
6         9         


        

Answer 1

You can use CTE and write a query as:

declare @StartDate DATE, @EndDate DATE
set @StartDate = '2013-09-01';
set @EndDate = '2013-09-30';

  WITH DateRange(Date) AS
     (
         SELECT
             @StartDate Date
         UNION ALL
         SELECT
             DATEADD(day, 1, Date) Date
         FROM
             DateRange
         WHERE
             Date < @EndDate
     )

     SELECT 'webshop',Date 
     FROM DateRange
     EXCEPT 
     SELECT DataSet,DateRange
     FROM ImportedDateRange
     WHERE DataSet='webshop'
     --You could remove Maximum Recursion level constraint by specifying a MaxRecusion of zero
     OPTION (MaxRecursion 10000);