我正在尝试编译一个非常简单的程序，该程序连接到数据库并打印数据库名称。我可以在命令行上编译，但无法在 Netbeans 中编译。我在 Ubuntu 10.04 上使用 Netbeans IDE 6.9.1，并使用 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;
}
我可以使用以下内容成功编译：
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)
任何人都可以提供任何关于为什么会失败的见解吗？我已经离开 C++ 一段时间了，所以不像以前那样善于找出哪里出了问题。
