编译 mariadb 的 C++ 连接器时“未定义对`sql::mariadb::get_driver_instance()'的引用”

如何解决编译 mariadb 的 C++ 连接器时“未定义对`sql::mariadb::get_driver_instance()'的引用”

大家好，我在 QT5 中有一个项目，它必须使用 C++ 连接到 mariadb 服务器，问题是当用 qmake 编译时，它返回几个未定义的引用错误，其中包含与 :: sql 相关的所有内容。

:-1: error: main.o: in function `printContacts(std::shared_ptr<sql::Statement>&)':

../test_server/main.cpp:12: error: undefined reference to `sql::SQLString::SQLString(char const*)'

../test_server/main.cpp:16: undefined reference to `sql::operator<<(std::ostream&,sql::SQLString const&)'

:-1: error: main.o: in function `std::pair<sql::SQLString const,sql::SQLString>::~pair()':

/usr/include/c++/11/bits/stl_pair.h:211: error: undefined reference to `sql::SQLString::~SQLString()'

:-1: error: /usr/include/c++/11/bits/stl_pair.h:211: undefined reference to `sql::SQLString::~SQLString()'

:-1: error: main.o: in function `std::pair<sql::SQLString const,sql::SQLString>::pair<char const (&) [5],char const (&) [8],true>(char const (&) [5],char const (&) [8])':

直接从控制台用 g ++ 编译时，通过将库作为参数传递，不包括 main.cpp 文件中的库，编译没有问题。

g++ -o test_server main.cpp -std=c++11 -lmariadbcpp

在 .pro 文件中，我创建了指向已安装的 mariadb 库的链接，没有任何问题。 test_server.pro。

QT -= gui

CONFIG += c++11 console

CONFIG -= app_bundle

SOURCES += \
        main.cpp

qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target


unix:CONFIG(release,debug|release): LIBS += -L/usr/lib64 -lmariadbcpp

unix {
INCLUDEPATH += /usr/include/mariadb -I..include
DEPENDPATH += /usr/include/mariadb -I..include
}

在主函数中的代码如下：main.cpp

#include <QCoreApplication>
#include <iostream>
#include <mariadb/conncpp.hpp>


void printContacts(std::shared_ptr<sql::Statement> &stmnt)
{
   try
   {
     std::unique_ptr<sql::ResultSet> res(
            stmnt->executeQuery("SHOW DATABASES")
         );
      while (res->next())
      {
         std::cout << "- "
            << res->getString(1)
            << " "  << std::endl;
      }
   }
  catch (sql::SQLException& e)
   {
      std::cerr << "Error printing contacts: "
         << e.what() << std::endl;
   }
}


int main(int argc,char *argv[])
{
    QCoreApplication a(argc,argv);

    try
      {
        sql::Driver* driver = sql::mariadb::get_driver_instance();
        sql::SQLString url("jdbc:mariadb://127.0.0.1:3306/bt");
        sql::Properties properties({
              {"user","mysuser"},{"password","mypassword"}
           });
         std::unique_ptr<sql::Connection> conn(driver->connect(url,properties));
         std::shared_ptr<sql::Statement> stmnt(conn->createStatement());
         printContacts(stmnt);
         conn->close();
      }
      catch (sql::SQLException &e)
      {
         std::cerr << "Error Connecting to MariaDB Platform: "
            << e.what() << std::endl;
         return 1;
      }
    return a.exec();
}

构建输出

22:08:05: Running steps for project test_server...
22:08:05: Configuration unchanged,skipping qmake step.
22:08:05: Starting: "/usr/bin/make" -j4
g++ -c -pipe -g -std=gnu++11 -Wall -Wextra -D_REENTRANT -fPIC -DQT_QML_DEBUG -DQT_CORE_LIB -I../test_server -I. -I/usr/include/mariadb -I-I..include -I/usr/include/qt5 -I/usr/include/qt5/QtCore -I. -I/../lib64/qt5/mkspecs/linux-g++ -o main.o ../test_server/main.cpp
g++  -o test_server main.o   /usr/lib64/libQt5Core.so -lpthread   
/usr/bin/ld: main.o: in function `printContacts(std::shared_ptr<sql::Statement>&)':
/home/chls/Documentos/Mayoreo/Mayoreo/build-test_server-Desktop-Debug/../test_server/main.cpp:12: undefined reference to `sql::SQLString::SQLString(char const*)'
/usr/bin/ld: /home/chls/Documentos/Mayoreo/Mayoreo/build-test_server-Desktop-Debug/../test_server/main.cpp:12: undefined reference to `sql::SQLString::~SQLString()'
/usr/bin/ld: /home/chls/Documentos/Mayoreo/Mayoreo/build-test_server-Desktop-Debug/../test_server/main.cpp:16: undefined reference to `sql::operator<<(std::ostream&,sql::SQLString const&)'
/usr/bin/ld: /home/chls/Documentos/Mayoreo/Mayoreo/build-test_server-Desktop-Debug/../test_server/main.cpp:16: undefined reference to `sql::SQLString::~SQLString()'
/usr/bin/ld: /home/chls/Documentos/Mayoreo/Mayoreo/build-test_server-Desktop-Debug/../test_server/main.cpp:25: undefined reference to `sql::SQLString::~SQLString()'
/usr/bin/ld: /home/chls/Documentos/Mayoreo/Mayoreo/build-test_server-Desktop-Debug/../test_server/main.cpp:16: undefined reference to `sql::SQLString::~SQLString()'
/usr/bin/ld: main.o: in function `main':
/home/chls/Documentos/Mayoreo/Mayoreo/build-test_server-Desktop-Debug/../test_server/main.cpp:34: undefined reference to `sql::mariadb::get_driver_instance()'
/usr/bin/ld: /home/chls/Documentos/Mayoreo/Mayoreo/build-test_server-Desktop-Debug/../test_server/main.cpp:35: undefined reference to `sql::SQLString::SQLString(char const*)'
/usr/bin/ld: /home/chls/Documentos/Mayoreo/Mayoreo/build-test_server-Desktop-Debug/../test_server/main.cpp:44: undefined reference to `sql::SQLString::~SQLString()'
/usr/bin/ld: /home/chls/Documentos/Mayoreo/Mayoreo/build-test_server-Desktop-Debug/../test_server/main.cpp:44: undefined reference to `sql::SQLString::~SQLString()'
/usr/bin/ld: main.o: in function `std::pair<sql::SQLString const,sql::SQLString>::~pair()':
/usr/include/c++/11/bits/stl_pair.h:211: undefined reference to `sql::SQLString::~SQLString()'
/usr/bin/ld: /usr/include/c++/11/bits/stl_pair.h:211: undefined reference to `sql::SQLString::~SQLString()'
/usr/bin/ld: main.o: in function `std::pair<sql::SQLString const,char const (&) [8])':
/usr/include/c++/11/bits/stl_pair.h:353: undefined reference to `sql::SQLString::SQLString(char const*)'
/usr/bin/ld: /usr/include/c++/11/bits/stl_pair.h:353: undefined reference to `sql::SQLString::SQLString(char const*)'
/usr/bin/ld: /usr/include/c++/11/bits/stl_pair.h:353: undefined reference to `sql::SQLString::~SQLString()'
/usr/bin/ld: main.o: in function `std::pair<sql::SQLString const,sql::SQLString>::pair<char const (&) [9],char const (&) [11],true>(char const (&) [9],char const (&) [11])':
/usr/include/c++/11/bits/stl_pair.h:353: undefined reference to `sql::SQLString::SQLString(char const*)'
/usr/bin/ld: /usr/include/c++/11/bits/stl_pair.h:353: undefined reference to `sql::SQLString::SQLString(char const*)'
/usr/bin/ld: /usr/include/c++/11/bits/stl_pair.h:353: undefined reference to `sql::SQLString::~SQLString()'
/usr/bin/ld: main.o: in function `std::less<sql::SQLString>::operator()(sql::SQLString const&,sql::SQLString const&) const':
/usr/include/c++/11/bits/stl_function.h:386: undefined reference to `sql::SQLString::operator<(sql::SQLString const&) const'
/usr/bin/ld: main.o: in function `std::pair<sql::SQLString const,sql::SQLString>::pair(std::pair<sql::SQLString const,sql::SQLString> const&)':
/usr/include/c++/11/bits/stl_pair.h:314: undefined reference to `sql::SQLString::SQLString(sql::SQLString const&)'
/usr/bin/ld: /usr/include/c++/11/bits/stl_pair.h:314: undefined reference to `sql::SQLString::SQLString(sql::SQLString const&)'
/usr/bin/ld: /usr/include/c++/11/bits/stl_pair.h:314: undefined reference to `sql::SQLString::~SQLString()'
/usr/bin/ld: main.o:(.data.rel.local.DW.ref._ZTIN3sql12SQLExceptionE[DW.ref._ZTIN3sql12SQLExceptionE]+0x0): undefined reference to `typeinfo for sql::SQLException'
collect2: error: ld returned 1 exit status
make: *** [Makefile:143: test_server] Error 1
22:08:05: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project test_server (kit: Desktop)
When executing step "Make"
22:08:05: Elapsed time: 00:00.