Re: How to cast VARCHAR to BYTEA and vice-versa? - Mailing list pgsql-sql

From Christoph Haller
Subject Re: How to cast VARCHAR to BYTEA and vice-versa?
Date
Msg-id 4236A630.E6952C1B@rodos.fzk.de
Whole thread Raw
In response to How to cast VARCHAR to BYTEA and vice-versa?  ("Moran.Michael" <Michael.Moran@IGT.com>)
List pgsql-sql
Seems my remembrance was wrong, ::TEXT::BYTEA causes 
ERROR: cannot cast type text to bytea 
on my 7.4.5 version too. 
Looking into "Other Binary String Functions" within the manual, 
sheds light on how to do it: 

::TEXT::BYTEA
Function decode(string text, type text) Return Type bytea 
select decode('123\\000456'::text, 'escape');  decode   
------------123\000456
(1 row)

::BYTEA::TEXT
Function encode(string bytea, type text) Return Type text
select encode('123\\000456'::bytea, 'escape');  encode   
------------123\000456
(1 row)

Sorry for the confusion I have caused, 
especially because there already was a correct answer 
sent by Ragnar. 

Regards, Christoph 


Lance Peterson wrote:
> 
> Christoph, is that recent functionality?  I'm running 7.4 and I get:
> ERROR: cannot cast type text to bytea
> 
> I get similar errors when trying to go the other direction.
> 
> On Mon, 14 Mar 2005 11:32:26 +0100, Christoph Haller <ch@rodos.fzk.de> wrote:
> > "Moran.Michael" wrote:
> > >
> > > Hello all,
> > >
> > > I have a table with a VARCHAR column that I need to convert to a BYTEA.
> > >
> > > How do I cast VARCHAR to BYTEA?
> > >
> > > The following doesn't seem to work as it yields the 'cannot cast varchar to
> > > bytea' error message:
> > >
> > >     varchar_data::bytea
> > >
> > > On the same topic, how do I do the reverse, that is, how to I cast from
> > > BYTEA back to VARCHAR?
> > >
> > > Thanks,
> > > -Michael Moran
> > >
> > >
> > As far as I remember
> > varchar_data::TEXT::BYTEA
> > works. Vice versa dto.
> > Be aware BYTEA data may contain character codes
> > unconvertable to VARCHAR, especially '\0'.
> >
> > Regards, Christoph
> >


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