Re: In a view, how do I cause fields with possible NULLs to be treated as a blank string in a replace operation?

Either use '' as some_type, or use COALESCE(some_type, '').

On Mon, Jun 27, 2011 at 9:53 AM, Asfand Qazi (Sanger Institute) <
aq2(dot)sanger(at)gmail(dot)com> wrote:

> Hello,
>
> So I have am playing with a view to test the feasibility of a
> technique for storing some data.
>
> It basically goes something like this:
>
> CREATE VIEW formatted_table AS
> SELECT name,
> replace(some_template, '@', some_type) AS some_field
> FROM some_table;
>
> some_template is something like 'foo(at)bar' or 'foobar' (note the
> missing template character).
>
> some_type is a single letter like 'a' or 'b', or it can be NULL.
>
> The above view works fine for rows where some_type is a letter, and
> some_field ends up as 'fooabar' or whatever.
>
> However, when some_type is NULL, some_field ends up as NULL as well.
> I understand that this is expected behaviour, but how do I cause the
> view to treat a some_type of NULL as an empty string, so that
> some_field simply ends up as 'foobar'?
>
> Hope that was clear.
>
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--
Rick Genter
rick(dot)genter(at)gmail(dot)com