Question

I have a query which returns all of the rows for three days ago:

SELECT * FROM table2 
 WHERE CONVERT(date, given_schedule)
 = CONVERT(date, DATEADD(d, -3, GETDATE()))

But I want to know limit the rows to only the hour relative to the current time. So for example, it is currently after 9:00 PM then I only want to retrieve the rows that occurred three days ago and between 9:00 and 10:00 PM.

Answer 1

SELECT columns FROM dbo.table2
WHERE 
    CONVERT(DATE, given_schedule) 
    = CONVERT(DATE, DATEADD(DAY, -3, CURRENT_TIMESTAMP))
AND 
    DATEPART(HOUR, given_schedule) 
    = DATEPART(HOUR, CURRENT_TIMESTAMP);

To address @Habo’s point, you could also do:

DECLARE @s SMALLDATETIME = CURRENT_TIMESTAMP;

SET @s = DATEADD(DAY, -3, DATEADD(MINUTE, -DATEPART(MINUTE, @s), @s));

SELECT columns FROM dbo.table2
  WHERE given_schedule >= @s
  AND given_schedule < DATEADD(HOUR, 1, @s);

This is, of course, most useful if there is actually an index with given_schedule as the leading column.