Poco ODBC library undefined reference error

问题

I am in process to build a program that establish connectivity with MySQL database using ODBC. I am using Poco-Data-ODBC library for the same. I am getting the following error :

D:\Hardware\Windows\PocoODBC/PocoODBC.cpp:27: undefined reference to `__imp__ZN4Poco4Data4ODBC9Connector17registerConnectorEv'
D:\Hardware\Windows\PocoODBC/PocoODBC.cpp:34: undefined reference to `__imp__ZN4Poco4Data4ODBC9Connector19unregisterConnectorEv'
D:\Hardware\Windows\PocoODBC/PocoODBC.cpp:41: undefined reference to `__imp__ZN4Poco4Data4ODBC9Connector19unregisterConnectorEv'

Build Command :

g++     -o dist/Debug/Msys64_MinGW-w64_7.3.0-Windows/pocoodbc build/Debug/Msys64_MinGW-w64_7.3.0-Windows/PocoODBC.o build/Debug/Msys64_MinGW-w64_7.3.0-Windows/main.o
-L/C/msys64/mingw64/bin -L/C/Program\ Files/MySQL/Connector.ODBC\ 5.3 -lodbc32 -lPocoDataODBC -lws2_32 -lPocoFoundation -lPocoData

Linked Libraries :

-lodbc32

-lPocoDataODBC

-lws2_32

-lPocoFoundation

-lPocoData

Source Code :

#include <iostream>
#include <vector>
#include <array>
#include <queue>
#include <string>
#include <sstream>
#include <cstring>
#include <cstdlib>
#include <cstdint>
#include <windows.h>

#define POCO_WIN32_UTF8

#include <Poco/Event.h>
#include <Poco/Data/Data.h>
#include <Poco/Data/Session.h>
#include <Poco/Data/RecordSet.h>
#include <Poco/Data/ODBC/Connector.h>

Poco::Data::ODBC::Connector::registerConnector();
    //const std::string ConnectionString("DRIVER={MySQL ODBC 8.0 Driver}; SERVER=localhost; DATABASE=test; USER=venu; PASSWORD=venu; OPTION=3;");
    const std::string ConnectionString("Dsn=HamsterPro20 ANSI; USER=root; PASSWORD=tantra@123; OPTION=3;");
    Poco::Data::Session session("ODBC", ConnectionString);
    if(not session.isConnected())
    {
        std::cout << "Session connection failed" << std::endl;
        Poco::Data::ODBC::Connector::unregisterConnector();
        return false;
    }
    else
    {
        std::cout << "Session connection success" << std::endl;
        session.close();
        Poco::Data::ODBC::Connector::unregisterConnector();
        return true;
    }

Platform: x64
OS: Windows 10 Pro
Development Environment: Msys64 (mingw-w64 )
IDE: Netbeans
Compiler: mingw-w64-x86_64-gcc 7.3.0-2

回答1:

I asked for the same problem here, but I've found the solution myself (also published in my question):

When compiling files for Data/ODBC I got some warnings, something like

redeclared without dllimport attribute: previous dllimport ignored

for files Data\ODBC\src\Extractor.cpp and Data\ODBC\src\Preparator.cpp.

Regardless these warnings, the files are compiled. But when the library is generated it lacks of entry points, as exposed in my question.

The solution is to add #include "Poco/Foundation.h" at the beginning of Data\ODBC\src\Extractor.cpp and Data\ODBC\src\Preparator.cpp.

I could guess this from this poco issue.

来源：https://stackoverflow.com/questions/50168733/poco-odbc-library-undefined-reference-error

标签

c++

odbc

poco-libraries