Question

In an SQL Server procedure, I need to get all rows matching some constraints(simple where conditions), and then group them by month.

The goal is to create a graph(in Sql server reporting services), which display all data.

I’ve already something like this:

Select Count(*) AS Count, Month(a.issueDate) AS Month, Year(a.issueDate) AS Year
FROM MyTable a
WHERE
....
GROUP BY YEAR(a.issueDate), MONTH(a.issueDate)

I got my data, I got my graph, but the problem is that if I’ve NOT any rows in “MyTable“, which match my Where conditions, I won’t have any rows.

The result is that I’ve a graph Starting with january, skipping february, and then displaying march.

I cannot post-process data since it’s directly connected to the SQL Server Reporting Services report.

Since I have this problem for ~20 stored procedure, I will appreciate to have the simpliest way of doing it.

Thank you very much for your advices

Answer 1

Let’s say you want a specific year:

DECLARE @year INT;
SET @year = 2012;

DECLARE @start SMALLDATETIME;
SET @start = DATEADD(YEAR, @year-1900, 0);

;WITH y AS (SELECT TOP (12) rn = ROW_NUMBER() OVER (ORDER BY [object_id])-1
  FROM sys.all_objects ORDER BY [object_id])
SELECT DATEADD(MONTH, y.rn, @start), COUNT(t.issueDate)
  FROM y
  LEFT OUTER JOIN dbo.MyTable AS t
  ON t.issueDate >= DATEADD(MONTH, y.rn, @start)
  AND t.issueDate < DATEADD(MONTH, y.rn + 1, @start)
GROUP BY DATEADD(MONTH, y.rn, @start);

If it’s not a specific year, then you can do it slightly differently to cover any date range, as long as you provide the 1st day of the 1st month and the 1st day of the last month (or pass 4 integers and construct the dates manually):

DECLARE @startdate SMALLDATETIME, @enddate SMALLDATETIME;
SELECT @startdate = '20111201', @enddate = '20120201';

;WITH y AS (SELECT TOP (DATEDIFF(MONTH, @startdate, @enddate)+1)
    rn = ROW_NUMBER() OVER (ORDER BY [object_id])-1
    FROM sys.all_objects ORDER BY [object_id]
)
SELECT DATEADD(MONTH, y.rn, @startdate), COUNT(t.issueDate)
  FROM y
  LEFT OUTER JOIN dbo.MyTable AS t
  ON t.issueDate >= DATEADD(MONTH, y.rn, @startdate)
  AND t.issueDate < DATEADD(MONTH, y.rn + 1, @startdate)
GROUP BY DATEADD(MONTH, y.rn, @startdate);