public inbox for [email protected]  

help / color / mirror / Atom feed

From: Igor Korot <[email protected]>
To: David G. Johnston <[email protected]>
Cc: Laurenz Albe <[email protected]>
Cc: pgsql-generallists.postgresql.org <[email protected]>
Subject: Re: PQexecPrepared() question
Date: Thu, 18 Dec 2025 18:10:45 -0600
Message-ID: <CA+FnnTwZUo-ZRZ4if_ngXXkYgtOCsmMp1uFpsMFkG5AOmRxX4Q@mail.gmail.com> (raw)
In-Reply-To: <CAKFQuwZaf2quGaqsGAj4+rVVCebOwU3JjbMUJPxxj6NeF_O_gA@mail.gmail.com>
References: <CA+FnnTygjVvSmzTHnvteuL4KEC=0P_+mF8Kn84JtNGZWUGxpUA@mail.gmail.com>
	<[email protected]>
	<CA+FnnTxO6kam9=mRonvsnUA1OxJxdDdQsj+ubdgFNNb9b3WMPQ@mail.gmail.com>
	<[email protected]>
	<CA+FnnTzE34VJWR7xkymaKEwXiiQ8j3o03m0+qcQsRr2JkRQLwQ@mail.gmail.com>
	<CAKFQuwZaf2quGaqsGAj4+rVVCebOwU3JjbMUJPxxj6NeF_O_gA@mail.gmail.com>

Hi, David,

On Thu, Dec 18, 2025 at 7:41 AM David G. Johnston
<[email protected]> wrote:
>
> On Thu, Dec 18, 2025 at 8:20 AM Igor Korot <[email protected]> wrote:
>>
>> Imagine following scenario:
>>
>> I have 2 machines. One is running PG server on *nix. Second is my app on Windows.
>>
>> An application starts for the first time.
>>
>> What is “clientencoding in this case?
>
>
> This day in age, probably UTF-8; which is what most servers are initialized using.  If you aren't having issues with encoding I suggest you just take for granted that the defaults work in 99% of the cases.  If you are having issues, share the details.

My code:

         for( int i = 0; i < PQntuples( res ); i++ )
         {
             std::wstring cat = m_pimpl->m_myconv.from_bytes(
PQgetvalue( res, i, 0 ) );
             std::wstring schema = m_pimpl->m_myconv.from_bytes(
PQgetvalue( res, i, 1 ) );
             std::wstring table = m_pimpl->m_myconv.from_bytes(
PQgetvalue( res, i, 2 ) );
             char *table_owner = PQgetvalue( res, i, 3 );
             pimpl.m_tableDefinitions[cat].push_back( TableDefinition(
cat, schema,  table ) );
             count++;
             paramValues = schema + L"." + table;
             params[0] = new char[paramValues.length() + 2];
             memset( params[0], '\0', paramValues.length() + 2 );
             std::wcstombs( params[0], paramValues.c_str(),
paramValues.length() );
             params[1] = new char[table.length() + 2];
             memset( params[1], '\0', table.length() + 2 );
             std::wcstombs( params[1], table.c_str(), table.length() );
             params[2] = new char[schema.length() + 2];
             memset( params[2], '\0', schema.length() + 2 );
             std::wcstombs( params[2], schema.c_str(), schema.length() + 2 );
             paramFormat[0] = paramFormat[1] = paramFormat[2] = 0;
             paramLength[0] = paramValues.length();
             paramLength[1] = table.length();
             paramLength[2] = schema.length();
             res8 = PQexecPrepared( m_db, "set_table_prop", 3, params,
paramLength, paramFormat, 0 );
             if( PQresultStatus( res8 ) != PGRES_COMMAND_OK )
             {
                 std::wstring err = m_pimpl->m_myconv.from_bytes(
PQerrorMessage( m_db ) );
                 errorMsg.push_back( L"Error executing query: " + err );
                 result = 1;
             }
             PQclear( res8 );
             delete[] params[0];
             params[0] = nullptr;
             delete[] params[1];
             params[1] = nullptr;
             delete[] params[2];
             params[2] = nullptr;
         }

And ths s what I have n the DB:

table_catalog | table_schema | table_name | table_type |
self_referencing_column_name | reference_generation |
user_defined_type_catalog | user_defined_type_schema |
user_defined_type_name | is_insertable_into | is_typed | commit_action
---------------+--------------+------------+------------+------------------------------+----------------------+---------------------------+--------------------------+-
-----------------------+--------------------+----------+---------------
draft         | public       | abcß       | BASE TABLE |
               |                      |                           |
                      |
                      | YES                | NO       |

Using my setup above and assumng my Win locale is en_US.UTF8 I can
successfullly retreve
that record but the insertion fails with

Invalid byte sequence for parameter $1 in UTF8

Thank you.

>
> David J.
>

view thread (10+ messages)  latest in thread

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected]
  Subject: Re: PQexecPrepared() question
  In-Reply-To: <CA+FnnTwZUo-ZRZ4if_ngXXkYgtOCsmMp1uFpsMFkG5AOmRxX4Q@mail.gmail.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox