c++ - 无法使用 Netbeans 编译 libpqxx 测试

Question

我正在尝试编译一个非常简单的程序来连接数据库并打印数据库名称。我可以在命令行上进行编译，但无法在 Netbeans 中进行编译。我在 Ubuntu 10.04 上使用 Netbeans IDE 6.9.1，并使用通过 apt-get 安装的 g++ 4.4.3 和 libpqxx 2.6.9。代码如下:

#include <iostream>
#include <pqxx/connection>

using namespace std;
using namespace pqxx;

int main(int argc, char *argv[])
{
  try
  {
    // Set up a connection to the backend
    connection C(argv[1]);
    cout << C.dbname() << endl;
  }
  catch (const exception &e)
  {
    // All exceptions thrown by libpqxx are derived from std::exception
    cerr << "Exception: " << e.what() << endl;
    return 2;
  }
  return 0;
}

我可以使用以下命令成功编译:

g++ -g -o example -L/usr/lib/ -lpqxx -lpq dbtest001.cpp

Netbeans 失败了:

"/usr/bin/make" -f nbproject/Makefile-Debug.mk QMAKE= SUBPROJECTS= .build-conf
make[1]: Entering directory `/home/dev/work/cpptest'
"/usr/bin/make"  -f nbproject/Makefile-Debug.mk dist/Debug/GNU-Linux-x86/cpptest
make[2]: Entering directory `/home/dev/work/cpptest'
mkdir -p build/Debug/GNU-Linux-x86
rm -f build/Debug/GNU-Linux-x86/main.o.d
g++    -c -g -MMD -MP -MF build/Debug/GNU-Linux-x86/main.o.d -o build/Debug/GNU-Linux-x86/main.o main.cpp
mkdir -p dist/Debug/GNU-Linux-x86
g++     -o dist/Debug/GNU-Linux-x86/cpptest build/Debug/GNU-Linux-x86/main.o  
make[2]: Leaving directory `/home/dev/work/cpptest'
make[1]: Leaving directory `/home/dev/work/cpptest'
build/Debug/GNU-Linux-x86/main.o: In function `main':
/home/dev/work/cpptest/main.cpp:13: undefined reference to `pqxx::connection_base::dbname()'
build/Debug/GNU-Linux-x86/main.o: In function `connect_direct':
/usr/include/pqxx/connection.hxx:84: undefined reference to `pqxx::connectionpolicy::connectionpolicy(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
/usr/include/pqxx/connection.hxx:84: undefined reference to `vtable for pqxx::connect_direct'
build/Debug/GNU-Linux-x86/main.o: In function `~connect_direct':
/usr/include/pqxx/connection.hxx:82: undefined reference to `vtable for pqxx::connect_direct'
/usr/include/pqxx/connection.hxx:82: undefined reference to `pqxx::connectionpolicy::~connectionpolicy()'
build/Debug/GNU-Linux-x86/main.o: In function `basic_connection':
/usr/include/pqxx/basic_connection.hxx:61: undefined reference to `pqxx::connection_base::connection_base(pqxx::connectionpolicy&)'
/usr/include/pqxx/basic_connection.hxx:62: undefined reference to `pqxx::connection_base::init()'
build/Debug/GNU-Linux-x86/main.o: In function `~basic_connection':
/usr/include/pqxx/basic_connection.hxx:70: undefined reference to `pqxx::connection_base::close()'
collect2: ld returned 1 exit status
make[2]: *** [dist/Debug/GNU-Linux-x86/cpptest] Error 1
make[1]: *** [.build-conf] Error 2
make: *** [.build-impl] Error 2

BUILD FAILED (exit value 2, total time: 622ms)

任何人都可以提供有关失败原因的任何见解吗？我已经离开 C++ 一段时间了，所以我不像以前那样敏锐地找出哪里出了问题。

Answer 1

g++     -o dist/Debug/GNU-Linux-x86/cpptest build/Debug/GNU-Linux-x86/main.o

您会注意到 Netbeans 没有像您那样将 -L 和 -l 选项添加到链接器命令。这导致了“ undefined reference ”错误——它没有将您的程序链接到 pqxx 库。

您需要编辑您的 Netbeans 项目以设置正确的库路径和依赖项。