Re: Blowback from text conversion changes

On Mon, 25 Jun 2007 17:56:28 +0100
Gregory Stark <stark(at)enterprisedb(dot)com> wrote:
>
> This seems odd. It's not deciding that it's ambiguous or coming from another
> datatype for which no implicit cast exists. It knows perfectly well that it
> wants to convert to text but fails?
>
>
> postgres=# select 'a'||b from (select 'b' as b) as x;
> ERROR: failed to find conversion function from unknown to text

It isn't the destination type that is the problem here but the source.
I suppose that it could default 'b' to text but really, that isn't
necessarily what '' signifies. How about '2007-06-25'? Is that text,
date or timestamp? Try this.

select 'a'||b from (select 'b'::text as b) as x;

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