How to Generate a Comprehensive Date Range with Populated Zero Values for Missing Data?

Generating a Comprehensive Date Range with Populated Data

In a database, it is often necessary to retrieve data within a specific date range. However, when data is missing for certain dates, it can be useful to display zeros instead of leaving the columns empty. This ensures that the entire date range is represented, providing a more comprehensive view of the data.

Problem:

You have a table containing date and value data and need to retrieve all dates within a specified range. If there is no row for a particular date, you want to display zero for all columns.

Solution:

This can be achieved by creating a set of dates using a recursive common table expression (CTE) and then performing a left join with the existing data table. The CTE generates a series of dates within the specified range. The left join matches the generated dates with the existing rows, filling in any missing values with zeros using the ISNULL() function.

;with d(date) as (
  select cast('10/01/2012' as datetime)
  union all
  select date+1
  from d
  where date < '10/15/2012'
  )
select t.ID, d.date CDate, isnull(t.val, 0) val
from d
left join temp t
       on t.CDate = d.date
order by d.date
OPTION (MAXRECURSION 0)

The MAXRECURSION option specifies the maximum number of recursive iterations allowed. In this case, since the date range is small (15 days), we can set it to 0 to allow unlimited iterations.

By executing this query, you will obtain a complete dataset that includes all dates within the specified range. Any missing dates will be populated with zeros, providing a comprehensive representation of the data.

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