#ORACLE WEEK NUMBER STARTING SUNDAY HOW TO#
#ORACLE WEEK NUMBER STARTING SUNDAY REGISTRATION#
#ORACLE WEEK NUMBER STARTING SUNDAY PLUS#

Here's the expression:ĭATEADD(week, DATEDIFF(week, -1, RegistrationDate), -1) AS Sunday We'll start with Sunday, since it is easier to explain. Option 1: Sunday as the First Day of the Week We'll start with discussing how you can find the first day of the week in either of those styles. There are two common ways to define the first day of the week: Sunday (typically used in the US) and Monday (typically used in Europe). However, if you need the precise date for the first day of the week, this won't do. This solution may be good enough if you're simply working interactively with data and need an approximation of when an event happened. If there are no registrations on the first day of the week, the query will show you the second day of the week as the WeekStart label. Of course, this solution is by no means perfect it assumes that the events you're counting (in this case, registrations) occur every day.

#ORACLE WEEK NUMBER STARTING SUNDAY REGISTRATION#

This query shows the number and the minimal registration date of each week (in other words, the first day of the week). The Hack: Using the MIN() Functionīefore we discuss the proper ways to compute the first day of the week in SQL Server, let's talk about a trick you can use to show a readable label for a week – the MIN() function:

#ORACLE WEEK NUMBER STARTING SUNDAY HOW TO#

In this article, we'll show you how to get the first day of the week in SQL Server. After all, how do we know what 'week 22' means? Is it in April, May, or June? It's better to display a date associated with each week, i.e.

The query displays the week number as the label for the week. The result looks something like this: Week ORDER BY DATEPART(week, RegistrationDate) GROUP BY DATEPART(week, RegistrationDate) The query might look like this:ĭATEPART(week, RegistrationDate) AS Week, By moving the anchor date slightly, you can hardcode any day as the first day of a week.Ĭorrection to your example: if today is 02/mar/2018 then start date is 24/feb/2018 but end date is 02/mar/2018, not 03/mar/2018.In the previous article, we talked about how you can use the SQL Server DATEPART() function with week or iso_week to group events by week.

#ORACLE WEEK NUMBER STARTING SUNDAY PLUS#

The end date is obviously the start date plus 6 days. This offset is subtracted from today, giving the closest Saturday before today. (You could use any Saturday before your oldest 'today' as the anchor.) The modulo (MOD) expression returns 0 if today is Saturday, 1 if it is Sunday, etc. The above query uses the Julian date (2415026) of the first Saturday in the 20th century (January 6th, 1900) as an anchor point. If you want to hardcode the week start to Saturday and make it independent of NLS settings, then you need to do some more complex date arithmetic, because TRUNC does not accept NLS_TERRITORY as a direct parameter:

It will start on Saturday in Arabic countries. The above query adapts to the week definition for a given territory: the week will start on Sunday in US and on Monday in Europe. If you can control the NLS territory setting (or even better: you want to adapt to it), then the simplest solution is to use TRUNC(SYSDATE,'D') and TRUNC(SYSDATE,'D')+6 :Īlter session set nls_territory='saudi arabia' įrom (select date ''+level today from dual connect by level<=10)

Oracle week number starting sunday