Re: Blob handling with Delphi...

On 04/13/11 1:28 AM, Durumdara wrote:
> Hi!
>
> PG9.0, Delphi 6, Zeos.
>
> I want to use PGSQL bytea field as normal BLOB field in Delphi.
>
> But when I insert a value into this field, for example all characters 
> (chr 0..255), and I fetch, and save it as blob stream into a file, I 
> got interesting result, not what I stored here previously.
>
> It is got \x prefix, and it is stored hexadecimal values.
>
> Is it normal, and I needs to convert this format to readable before I 
> use it, or I can get same result as in other databases/adapters (the 
> stream saved BlobField.SaveToFile have equal content as 
> BlobField.LoadFromFile)...
>
> Many DBAware components can show the blob directly as Image. With PG's 
> \x prefix this won't working well... :-(
>

in 9.0, the default encoding for BYTEA changed, and if your client 
interface doesnt undersatnd the new encoding (and isn't using the libpq 
entry points for handling byte encoding), it will fail like this..  
there's a SET variable that will restore the old behavior.

See 
http://www.postgresql.org/docs/current/static/runtime-config-client.html#GUC-BYTEA-OUTPUThttp://www.postgresql.org/docs/current/static/runtime-config-client.html#GUC-BYTEA-OUTPUT

     SET bytea_output='escape';

should revert to the previous behavior, and may well fix your problem 
with delphi