Re: PQexecPrepared() question

On 2025-12-21 00:39:23 -0500, Tom Lane wrote:
> Igor Korot <ikorot01(at)gmail(dot)com> writes:
> > I added the following code in my app:
> > res = PQexec( m_db, "SHOW client_encoding" );
> > auto value = PQgetvalue( res, 0, 0 );
> > PQclear( res );
> > and the value of the "value" variable is "UTF8".
>
> Okay ...
>
> > The exact error message is:
> > ERROR: invalid byte sequence for encoding UTF8: 0xdf
> > CONTEXT: unnamed portal parameter $1
> > on the INSERT.
>
> client_encoding governs both the encoding that the server will
> send, and the encoding that it expects to receive. You are
> sending a parameter string that is not valid UTF8.

As I see it, Igor has two options:

1) Send UTF8. wcstombs is the wrong tool for this, since it uses the
current locale which is obviously not using UTF-8. I don't program in
C++, but I'm pretty sure there is a portable way to encode a string
in UTF-8.
2) Figure out which encoding his locale is using and then set
client_encoding appropriately. The first step to do that is to find
the current locale.
Igor, add
#include <ctype.h>
...
char *current_locale = setlocale(LC_CTYPE, "");
to your code. What's the value of current_locale?

I think 1) is the better strategy, but them I've been a UTF-8 fan-boy
for over 30 years ;-).

hjp

--
_ | Peter J. Holzer | Story must make more sense than reality.
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| | | hjp(at)hjp(dot)at | -- Charles Stross, "Creative writing
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