- ADVENTUREWORKS2012 MONTH NUMBER CALENDAR YEAR HOW TO
- ADVENTUREWORKS2012 MONTH NUMBER CALENDAR YEAR CODE
- ADVENTUREWORKS2012 MONTH NUMBER CALENDAR YEAR SERIES
ADVENTUREWORKS2012 MONTH NUMBER CALENDAR YEAR SERIES
I hope you've enjoyed this little series it's a topic I've been meaning to revisit for ages.Creating a Date Dimension in a Tabular Model - Simple Talk Even with Canada's wacky metric system, 60 milliseconds is way better than about 10 *seconds* when it only incurred 200 KB on disk. However, it is quite clear that as your date range gets larger, particularly when you're dealing with a large source table, the Calendar table really demonstrates its worth – especially given its low memory footprint. And for a series of dates, at the lower end, you will not see much difference between the various techniques. For generating a series of numbers, the Numbers table approach wins out, but only marginally – even at 1,000,000 rows. Still, I think a Calendar table is a useful thing to have even if it isn't strictly necessary. n <= DATEDIFF ( DAY, 0, ) GROUP BY nĪt this point I'm not going to re-run all of the performance tests (exercise for the reader!), but I will assume that it will generate better or similar timings. OrderDate = DATEDIFF ( DAY, 0, ) AND n. OrderDate >= CONVERT ( DATETIME, ) AND s. To generate a Calendar table with 30 years of data, assuming you've already been convinced that having a Numbers table is a good thing, we can do this: For example, to store 30 years of dates, it requires less than 11,000 rows (exact number depends on how many leap years you span), and takes up a mere 200 KB. The same argument holds about how much space is really required and how fast access will be when the table is queried frequently.
If you are using date series for a lot of queries then you should consider having both a Numbers table and a Calendar table. This is a new one that we didn't talk much about in the previous two posts. SalesOrderID ) FROM d LEFT OUTER JOIN Sales.
ADVENTUREWORKS2012 MONTH NUMBER CALENDAR YEAR HOW TO
I'm going to make this set contain four rows, so that it is also easy to demonstrate how to cut off to exactly the series you need.įirst, we have a couple of variables to hold the start and end of the range we're interested in:ĭECLARE DATE = '', DATE = '' WITH e1 (n ) AS ( SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 ) ,Į2 (n ) AS ( SELECT 1 FROM e1 CROSS JOIN e1 AS b ) ,Į3 (n ) AS ( SELECT 1 FROM e2 CROSS JOIN ( SELECT TOP ( 37 ) n FROM e2 ) AS b ) ,ĭ (OrderDate ) AS ( SELECT TOP ( DATEDIFF ( DAY, , ) + 1 )ĭ = DATEADD ( DAY, ROW_NUMBER ( ) OVER ( ORDER BY N ) - 1, ) FROM e3
For this example I can replace complex sequence generators with a very simple union, since I only need three days.
With an established sequence of numbers (regardless of the method you choose), this task becomes much easier.
ADVENTUREWORKS2012 MONTH NUMBER CALENDAR YEAR CODE
That's more code than I even want to present here, never mind put in production, maintain, and have colleagues learn from. The old-fashioned way would be to create a #temp table, create a loop, have a variable that holds the current day, within the loop insert a row into the #temp table until the end of the range, and then use the #temp table to outer join to our source data. Let's start very simple, and pretend we want to run a report for three days, from January 1st through January 3rd, and include a row for every day.
Since we've already established multiple ways to derive a series of numbers, let's look at how the next step looks. In a previous post I mentioned that it is easy to derive a series of days from a series of numbers. While interesting, and useful in some scenarios, a more practical application is to generate a series of contiguous dates for example, a report that requires showing all the days of a month, even if some days had no transactions. Earlier in this series ( Part 1 | Part 2) we talked about generating a series of numbers using various techniques.