Comments on: Oracle conditions and how they handle NULL http://www.lifeaftercoffee.com/2005/09/28/oracle-conditions-and-how-they-handle-null/ because I don't believe in life before coffee... Wed, 23 Nov 2011 03:01:12 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: John http://www.lifeaftercoffee.com/2005/09/28/oracle-conditions-and-how-they-handle-null/comment-page-1/#comment-158135 John Thu, 26 Apr 2007 22:48:57 +0000 http://www.lifeaftercoffee.com/?p=75#comment-158135 Another crazy twist to this is with dates. If the date is null then you cannot compare it to a value date. So if you say something like SELECT * FROM table a where a.date1 a.date2 if date1 is null and there is a value in date2 then you would think that that row would return but it does not. If you want to include nulls in your not equal to comparator then something like this will work: SELECT * FROM table a where nvl(to_char(a.date1,'dd'),' ') a.date2 Another crazy twist to this is with dates. If the date is null then you cannot compare it to a value date. So if you say something like

SELECT * FROM table a
where a.date1 a.date2

if date1 is null and there is a value in date2 then you would think that that row would return but it does not.

If you want to include nulls in your not equal to comparator then something like this will work:

SELECT * FROM table a
where nvl(to_char(a.date1,’dd’),’ ‘) a.date2

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