On Tue, Jan 20, 2004 at 07:13:12PM +0530, Kenneth Gonsalves wrote:
> in postgres7.1 i had a table where an integer field could be null. There was
> no default value. a select statement like so:
> 'select * from table where field = null'
> would give all the rows where that field had no value.
> on porting to 7.3.2, this doesnt work. How to do this?
Because NULL can be read as "unknown". It does not make much sense to
test wheter a value of an integer is numerically equal to unknown. That is
why there is the IS operator:
where field IS null
"Nothing is as subjective as reality"
Reinoud van Leeuwen reinoud(dot)v(at)n(dot)leeuwen(dot)net
In response to
pgsql-sql by date
|Next:||From: Chris Bowlby||Date: 2004-01-20 15:04:02|
|Subject: Re: comparing nulls|
|Previous:||From: Luis Sousa||Date: 2004-01-20 14:30:57|
|Subject: Re: [SQL] Database diagram|