Re: string is sometimes null ? - Mailing list pgsql-general

From Stephan Szabo
Subject Re: string is sometimes null ?
Date
Msg-id 20040930073249.Q8163@megazone.bigpanda.com
Whole thread Raw
In response to Re: string is sometimes null ?  (Graeme Hinchliffe <graeme.hinchliffe@zeninternet.co.uk>)
List pgsql-general
On Thu, 30 Sep 2004, Graeme Hinchliffe wrote:

> > If monthcurr or username are null, the above will be null.
> > Anything || NULL => NULL.
>
> AH! thanks sorted it now.  That is not the behaviour I would have
> expected :)
>
> Is there a concatination operator that will not do this? IE
>
> if
>
> var1 || var2 || var3
>
> and var2 is null would result in just var1var3  ?

You can use coalesce as suggested... However, since you are building a
statement, think about what you want to do when either of those are NULL.
You might want to use an empty string, or perhaps instead of ='' you might
actually be wanting an IS NULL clause, etc...

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