SQL Query to return 24 hour, hourly count even when no values exist?

Question

I\'ve written a query that groups the number of rows per hour, based on a given date range.

SELECT CONVERT(VARCHAR(8),TransactionTime,101) + \' \' + CONVERT(         


        

Answer 1

So going back to using Remus' original function, I've re-used it in a recursive call and storing the results in a temp table:

DECLARE @count INT
DECLARE @NumDays INT
DECLARE @StartDate DATETIME
DECLARE @EndDate DATETIME
DECLARE @CurrentDay DATE

    DECLARE @tmp_Transactions TABLE 
    (
        StartHour DATETIME,
        TotalHourlyTransactions INT
    )   

SET @StartDate = '2000/02/10'
SET @EndDate = '2010/02/13'
SET @count = 0
SET @NumDays = DateDiff(Day, @StartDate, @EndDate)
WHILE @count < @NumDays 
    BEGIN
        SET @CurrentDay = DateAdd(Day, @count, @StartDate)
        INSERT INTO @tmp_Transactions (StartHour, TotalHourlyTransactions)
            SELECT  h.StartHour ,
                    t.TotalHourlyTransactions
            FROM    tvfGetDay24Hours(@CurrentDay) AS h
                    OUTER APPLY ( SELECT    COUNT(TransactionID) AS TotalHourlyTransactions
                                  FROM      [dbo].[TerminalTransactions]
                                  WHERE     TransactionTime BETWEEN h.StartHour AND h.EndHour
                                            AND TerminalId = 4
                                ) AS t
            ORDER BY h.StartHour
        SET @count = @Count + 1
    END 

SELECT *
FROM @tmp_Transactions