WHERE Clause to find all records in a specific month

Question

I want to be able to give a stored procedure a Month and Year and have it return everything that happens in that month, how do I do this as I can\'t compare between as some

Answer 1

Using the MONTH and YEAR functions as suggested in most of the responses has the disadvantage that SQL Server will not be able to use any index there may be on your date column. This can kill performance on a large table.

I would be inclined to pass a DATETIME value (e.g. @StartDate) to the stored procedure which represents the first day of the month you are interested in.

You can then use

SELECT ... FROM ...
WHERE DateColumn >= @StartDate 
AND DateColumn < DATEADD(month, 1, @StartDate)

If you must pass the month and year as separate parameters to the stored procedure, you can generate a DATETIME representing the first day of the month using CAST and CONVERT then proceed as above. If you do this I would recommend writing a function that generates a DATETIME from integer year, month, day values, e.g. the following from a SQL Server blog.

create function Date(@Year int, @Month int, @Day int)
returns datetime
as
    begin
    return dateadd(month,((@Year-1900)*12)+@Month-1,@Day-1)
    end
go

The query then becomes:

SELECT ... FROM ...
WHERE DateColumn >= Date(@Year,@Month,1)
AND DateColumn < DATEADD(month, 1, Date(@Year,@Month,1))