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))

Answer 2

One way would be to create a variable that represents the first of the month (ie 5/1/2009), either pass it into the proc or build it (concatenate month/1/year). Then use the DateDiff function.

WHERE DateDiff(m,@Date,DateField) = 0

This will return anything with a matching month and year.

Answer 3

SELECT * FROM yourtable WHERE yourtimestampfield LIKE 'AAAA-MM%';

Where AAAA is the year you want and MM is the month you want

Answer 4

More one tip very simple. You also could use to_char function, look:

For Month:

to_char(happened_at , 'MM') = 01

For Year:

to_char(happened_at , 'YYYY') = 2009

For Day:

to_char(happened_at , 'DD') = 01

to_char funcion is suported by sql language and not by one specific database.

I hope help anybody more...

Abs!