CODEWITHSUNDEEP
sqlsql-server-2008
Tarks
Tarks

Reputation: 4247

How to write a WHERE Clause to find all records in a specific month?

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 months have different numbers of days etc.?

What's the best way to do this? Can I just ask to compare based on the year and month?

Thanks.

Upvotes: 122

Views: 585229

Answers (10)

Marcelo Rebouças
Marcelo Rebouças

Reputation: 699

More one tip very simple to oracle db. 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!

Upvotes: 8

user2022742
user2022742

Reputation: 11

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

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

Upvotes: -4

onedaywhen
onedaywhen

Reputation: 57093

I find it easier to pass a value as a temporal data type (e.g. DATETIME) then use temporal functionality, specifically DATEADD and DATEPART, to find the start and end dates for the period, in this case the month e.g. this finds the start date and end date pair for the current month, just substitute CURRENT_TIMESTAMP for you parameter of of type DATETIME (note the 1990-01-01 value is entirely arbitrary):

SELECT DATEADD(M, 
          DATEDIFF(M, '1990-01-01T00:00:00.000', CURRENT_TIMESTAMP), 
          '1990-01-01T00:00:00.000'), 
       DATEADD(M, 
          DATEDIFF(M, '1990-01-01T00:00:00.000', CURRENT_TIMESTAMP), 
          '1990-01-31T23:59:59.997')

Upvotes: 1

to StackOverflow
to StackOverflow

Reputation: 124794

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))

Upvotes: 22

Andomar
Andomar

Reputation: 238296

As an alternative to the MONTH and YEAR functions, a regular WHERE clause will work too:

select *
from yourtable
where '2009-01-01' <= datecolumn and datecolumn < '2009-02-01'

Upvotes: 5

Mike Bennett
Mike Bennett

Reputation: 345

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.

Upvotes: 0

Shalom Craimer
Shalom Craimer

Reputation: 21469

I think the function you're looking for is MONTH(date). You'll probably want to use 'YEAR' too.

Let's assume you have a table named things that looks something like this:

id happend_at
-- ----------------
1  2009-01-01 12:08
2  2009-02-01 12:00
3  2009-01-12 09:40
4  2009-01-29 17:55

And let's say you want to execute to find all the records that have a happened_at during the month 2009/01 (January 2009). The SQL query would be:

SELECT id FROM things 
   WHERE MONTH(happened_at) = 1 AND YEAR(happened_at) = 2009

Which would return:

id
---
1
3
4

Upvotes: 266

Temple
Temple

Reputation: 1079

Something like this should do it:

select * from yourtable where datepart(month,field) = @month and datepart(year,field) = @year

Alternatively you could split month and year out into their own columns when creating the record and then select against them.

Iain

Upvotes: 0

The Lazy DBA
The Lazy DBA

Reputation: 1522

Can I just ask to compare based on the year and month?

You can. Here's a simple example using the AdventureWorks sample database...

DECLARE @Year       INT
DECLARE @Month      INT

SET @Year = 2002
SET @Month = 6

SELECT 
    [pch].* 
FROM 
    [Production].[ProductCostHistory]   pch
WHERE
    YEAR([pch].[ModifiedDate]) = @Year
AND MONTH([pch].[ModifiedDate]) = @Month

Upvotes: 1

Gromer
Gromer

Reputation: 9931

If you're using SQL Server, look into DATEPART.

http://msdn.microsoft.com/en-us/library/ms174420(SQL.90).aspx

DATEPART(mm, [THE DATE YOU'RE LOOKING AT])

You can then use normal integer logic with it. Same for year, just use yy instead of mm.

Upvotes: 2

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