Thursday, 13 January 2011

Create and fill Time dimension

Case
Is there an easy way to create and populate a time(/date) dimension?

Solution
Creating a time dimension is usually done once and probably not in SSIS, but with a TSQL script.
For each new assignment I use this script and adjust it to the requirements for that particular assignment .
-- Delete time dimension if it already exists.
IF Exists(Select Name from sysobjects where name = 'Dim_Time')
BEGIN
    Drop Table Dim_Time
END
GO

-- Standard options for creating tables
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

-- Create your dimension table
-- Adjust to your own needs
Create Table dbo.Dim_Time
(
    Dateid int IDENTITY (1,1) PRIMARY KEY CLUSTERED,
    Date date,
    DateString varchar(10),
    Day int,
    DayofYear int,
    DayofWeek int,
    DayofWeekName varchar(10),
    Week int,
    Month int,
    MonthName varchar(10),
    Quarter int,
    Year int,
    IsWeekend bit,
    IsLeapYear bit
)

-- Declare and set variables for loop
Declare
@StartDate datetime,
@EndDate datetime,
@Date datetime

Set @StartDate = '2000/01/01'
Set @EndDate = '2020/12/31'
Set @Date = @StartDate

-- Loop through dates
WHILE @Date <=@EndDate
BEGIN
    -- Check for leap year
    DECLARE @IsLeapYear BIT
    IF ((Year(@Date) % 4 = 0) AND (Year(@Date) % 100 != 0 OR Year(@Date) % 400 = 0))
    BEGIN
        SELECT @IsLeapYear = 1
    END
    ELSE
    BEGIN
        SELECT @IsLeapYear = 0
    END

    -- Check for weekend
    DECLARE @IsWeekend BIT
    IF (DATEPART(dw, @Date) = 1 OR DATEPART(dw, @Date) = 7)
    BEGIN
        SELECT @IsWeekend = 1
    END
    ELSE
    BEGIN
        SELECT @IsWeekend = 0
    END

    -- Insert record in dimension table
    INSERT Into Dim_Time
    (
    [Date],
    [DateString],
    [Day],
    [DayofYear],
    [DayofWeek],
    [Dayofweekname],
    [Week],
    [Month],
    [MonthName],
    [Quarter],
    [Year],
    [IsWeekend],
    [IsLeapYear]
    )
    Values
    (
    @Date,
    CONVERT(varchar(10), @Date, 105), -- See links for 105 explanation
    Day(@Date),
    DATEPART(dy, @Date),
    DATEPART(dw, @Date),
    DATENAME(dw, @Date),
    DATEPART(wk, @Date),
    DATEPART(mm, @Date),
    DATENAME(mm, @Date),
    DATENAME(qq, @Date),
    Year(@Date),
    @IsWeekend,
    @IsLeapYear
    )

    -- Goto next day
    Set @Date = @Date + 1
END
GO

Interesting links:
CAST and CONVERT:http://msdn.microsoft.com/en-us/library/ms187928.aspx
DATEPARThttp://msdn.microsoft.com/en-us/library/ms174420.aspx
DATENAMEhttp://msdn.microsoft.com/en-us/library/ms174395.aspx

Let me know if you have an interesting addition for this script that could help others.

8 comments:

  1. UR GOD man!!!

    ReplyDelete
  2. Very good script! Thanks.

    ReplyDelete
  3. thank you very much..! :)

    ReplyDelete
  4. Nice Article, Thanks......

    :-)

    ReplyDelete
  5. If anyone re-writes this for the BISM tabular model post it here....

    ReplyDelete
  6. Worked perfectly!
    Thanks!

    ReplyDelete

Please use the SSIS MSDN forum for general SSIS questions that are not about this post. I'm a regular reader of that forum and will gladly answer those questions over there.

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