Comments on: MySQL: find week start/end given week number http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/ Utterly random, incoherent and disjointed rants and ramblings... Sat, 22 Nov 2008 01:44:36 +0000 http://wordpress.org/?v=2.0.5 by: Luke Maciak http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-10227 Tue, 23 Sep 2008 17:47:28 +0000 http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-10227 @<a href="#comment-10226" rel="nofollow">Sid</a>: What do you mean? I think it is sort of self explanatory. @aStart will be the date exactly a week before today @aEnd will be a week from @aStart - which is today @aStartlastweek will be a date 1 week prior to @aStart And so on. When it says: <pre lang="sql">SET @foo = @bar - INTERVAL n WEEK</pre> it just means to count back n weeks from the date in @bar and put the result in @foo. The last 4 lines are just assignments. Does that make sense? @Sid: What do you mean? I think it is sort of self explanatory.

@aStart will be the date exactly a week before today
@aEnd will be a week from @aStart - which is today
@aStartlastweek will be a date 1 week prior to @aStart

And so on. When it says:

SET @foo = @bar - INTERVAL n WEEK

it just means to count back n weeks from the date in @bar and put the result in @foo. The last 4 lines are just assignments.

Does that make sense?

]]> by: Sid http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-10226 Tue, 23 Sep 2008 17:28:55 +0000 http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-10226 I have a script which has the following in the beginning, can someone explains what does it mean in mysql: <pre lang="sql">SET @aStart = CURDATE() - INTERVAL 1 WEEK; SET @aEnd = @aStart + INTERVAL 1 WEEK; SET @aStartlastweek = @aStart - INTERVAL 1 WEEK; SET @aEndlastweek = @aEnd - INTERVAL 1 WEEK; SET @aStartlast2week = @aStart - INTERVAL 2 WEEK; SET @aEndlast2week = @aEnd - INTERVAL 2 WEEK; SET @aStartlast3week = @aStart - INTERVAL 3 WEEK; SET @aEndlast3week = @aEnd - INTERVAL 3 WEEK; SET @aStartlast4week = @aStart - INTERVAL 4 WEEK; SET @aEndlast4week = @aEnd - INTERVAL 4 WEEK; SET @bStartNorm = 5; SET @bEndNorm = 23; SET @bRspCode = 999; SET @bMaxAvg = 120;</pre> I have a script which has the following in the beginning, can someone explains what does it mean in mysql:

SET @aStart = CURDATE() - INTERVAL 1 WEEK;  
SET @aEnd = @aStart + INTERVAL 1 WEEK;
SET @aStartlastweek = @aStart - INTERVAL 1 WEEK;
SET @aEndlastweek = @aEnd - INTERVAL 1 WEEK;
SET @aStartlast2week = @aStart - INTERVAL 2 WEEK;
SET @aEndlast2week = @aEnd - INTERVAL 2 WEEK;
SET @aStartlast3week = @aStart - INTERVAL 3 WEEK;
SET @aEndlast3week = @aEnd - INTERVAL 3 WEEK;
SET @aStartlast4week = @aStart - INTERVAL 4 WEEK;
SET @aEndlast4week = @aEnd - INTERVAL 4 WEEK;
 
 
SET @bStartNorm = 5;
SET @bEndNorm = 23;
SET @bRspCode = 999;
SET @bMaxAvg  = 120;
]]> by: Julio http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-9761 Thu, 31 Jul 2008 23:52:55 +0000 http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-9761 i have a question... how can i group by weeks... but starting on wednesday or tuesday? i have a question… how can i group by weeks… but starting on wednesday or tuesday?

]]> by: olivier http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-8341 Wed, 05 Mar 2008 21:11:46 +0000 http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-8341 For iso weeks (week starting on mondays, week numbering starting at 1) you can get the first day of the week "week_id" of the year "year" using <code>DATE_ADD( MAKEDATE(year,1), INTERVAL( -(((DAYOFWEEK(MAKEDATE(year,1))+1)%7)-3) + (week_id-1)*7 ) DAY)</code> simple, no ? :) For iso weeks (week starting on mondays, week numbering starting at 1) you can get the first day of the week “week_id” of the year “year” using
DATE_ADD( MAKEDATE(year,1), INTERVAL( -(((DAYOFWEEK(MAKEDATE(year,1))+1)%7)-3) + (week_id-1)*7 ) DAY)
simple, no ? )

]]> by: Snehapadma SaaS http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-7536 Sun, 30 Dec 2007 04:10:46 +0000 http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-7536 Hi All! What if I want to aggregate data for periods between Monday and Sunday? Is there any straight forward way to do that? e.g. like setting up the first weekday as Monday in the system? This discussion shows that Firefox is popular. Hi All!

What if I want to aggregate data for periods between Monday and Sunday? Is there any straight forward way to do that? e.g. like setting up the first weekday as Monday in the system?

This discussion shows that Firefox is popular.

]]> by: Matt Wood http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-6576 Tue, 16 Oct 2007 13:34:19 +0000 http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-6576 This works... SELECT * FROM Table WHERE WEEK('Date',4) = 30; It shows all the dates that are in the week number 30. I use mode 4 as Week 1 is the first week of the year, starting with a Sunday. This works…

SELECT * FROM Table WHERE WEEK(’Date’,4) = 30;

It shows all the dates that are in the week number 30. I use mode 4 as Week 1 is the first week of the year, starting with a Sunday.

]]> by: Luke Maciak http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-6080 Thu, 06 Sep 2007 14:33:58 +0000 http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-6080 <strong>@Stuart</strong> - Thanks Stuart! Good tip! @Stuart - Thanks Stuart! Good tip!

]]> by: shaun http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-6077 Thu, 06 Sep 2007 12:28:08 +0000 http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-6077 select DATE_ADD('2007-09-07',INTERVAL(2-DAYOFWEEK('2007-09-07'))DAY); swipe the date with what ever date you want to pass select DATE_ADD(’2007-09-07′,INTERVAL(2-DAYOFWEEK(’2007-09-07′))DAY);

swipe the date with what ever date you want to pass

]]> by: Stuart http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-6076 Thu, 06 Sep 2007 09:53:39 +0000 http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-6076 I've been looking for an answer to this problem all morning and your solution worked great. I don't know if it has any performance benefits, but MySQL has a YEARWEEK() function which stops you having to group by WEEK() and YEAR(). I’ve been looking for an answer to this problem all morning and your solution worked great. I don’t know if it has any performance benefits, but MySQL has a YEARWEEK() function which stops you having to group by WEEK() and YEAR().

]]> by: Luke Maciak http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-5987 Thu, 30 Aug 2007 23:45:51 +0000 http://www.terminally-incoherent.com/blog/2006/09/22/mysql-find-week-startend-based-on-week-number/#comment-5987 Hehe. Wow, my MySQL-Fu is still strong. :) Glad I could help. Hehe. Wow, my MySQL-Fu is still strong. ) Glad I could help.

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