5

我正在尝试用 pqxx 编译一个非常简单的程序（什么都不做的示例），但无法做到。这是“程序”：

$猫xx.cpp 

#include <pqxx/pqxx>
using namespace pqxx;


int main() 
{
    connection conn("dbname=dout1");
    return 0;
}

我曾经尝试在 C++ 中编译的命令：

g++ -I /usr/local/include/ -L /usr/local/lib/ -l pqxx -I /opt/postgres_home/include/ -L /opt/postgres_home/lib/ -lpq xx.cpp

返回的消息：

/tmp/cc18wMEy.o: In function `pqxx::connect_direct::connect_direct(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
xx.cpp:(.text._ZN4pqxx14connect_directC1ERKSs[pqxx::connect_direct::connect_direct(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)]+0x1f): undefined reference to `pqxx::connectionpolicy::connectionpolicy(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
xx.cpp:(.text._ZN4pqxx14connect_directC1ERKSs[pqxx::connect_direct::connect_direct(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)]+0x2a): undefined reference to `vtable for pqxx::connect_direct'
/tmp/cc18wMEy.o: In function `pqxx::connect_direct::~connect_direct()':
xx.cpp:(.text._ZN4pqxx14connect_directD1Ev[pqxx::connect_direct::~connect_direct()]+0x13): undefined reference to `vtable for pqxx::connect_direct'
xx.cpp:(.text._ZN4pqxx14connect_directD1Ev[pqxx::connect_direct::~connect_direct()]+0x1f): undefined reference to `pqxx::connectionpolicy::~connectionpolicy()'
/tmp/cc18wMEy.o: In function `pqxx::basic_connection<pqxx::connect_direct>::basic_connection(char const*)':
xx.cpp:(.text._ZN4pqxx16basic_connectionINS_14connect_directEEC1EPKc[pqxx::basic_connection<pqxx::connect_direct>::basic_connection(char const*)]+0x2b): undefined reference to `pqxx::connection_base::connection_base(pqxx::connectionpolicy&)'
xx.cpp:(.text._ZN4pqxx16basic_connectionINS_14connect_directEEC1EPKc[pqxx::basic_connection<pqxx::connect_direct>::basic_connection(char const*)]+0xd6): undefined reference to `pqxx::connection_base::init()'
/tmp/cc18wMEy.o: In function `pqxx::basic_connection<pqxx::connect_direct>::~basic_connection()':
xx.cpp:(.text._ZN4pqxx16basic_connectionINS_14connect_directEED1Ev[pqxx::basic_connection<pqxx::connect_direct>::~basic_connection()]+0x17): undefined reference to `pqxx::connection_base::close()'
collect2: ld returned 1 exit status

如果我喜欢：

$ g++ -I /usr/local/include/pqxx -L /usr/local/lib/ -l pqxx -l pq xx.cpp

回报：

/usr/lib64/gcc/x86_64-slackware-linux/4.4.4/../../../../x86_64-slackware-linux/bin/ld: cannot find -lpq
collect2: ld returned 1 exit status

考虑：

$ cat /etc/ld.so.conf

/usr/local/lib
/usr/local/pgsql/lib                <-- just symlink to /opt/postgres_home/
/opt/postgres_home/lib
/usr/x86_64-slackware-linux/lib
/usr/lib64/seamonkey
/opt/kde3/lib64
/usr/lib64/jre1.6.0_16/lib/amd64

我真的不知道还能做什么，因为：

 # ls /opt/postgres_home/lib/libpq*                                                      
/opt/postgres_home/lib/libpq.a     /opt/postgres_home/lib/libpq.so.5.3
/opt/postgres_home/lib/libpq.so    /opt/postgres_home/lib/libpqwalreceiver.so
/opt/postgres_home/lib/libpq.so.5

路易斯

4

2 回答 2

12

After an email exchange with pqxx author Jeroen T. Vermeulen, I could manage to compile the 'program'. The idea was to place xx.cpp before -lpqxx -lpq So, the entire command is:

g++ -I /usr/local/include/pqxx/ -L /usr/local/lib/ -I /usr/local/pgsql/include/ -L /usr/local/pgsql/lib/ xx.cpp -lpqxx  -lpq

It works now.

于 2011-03-14T12:56:18.877 回答
2

在这里用一个简单的 g++ -lpqxx xx.cpp 为我工作，所以它看起来非常像一个损坏的安装。请注意，您不需要与 libpq 链接，因为如果您使用共享对象，libpqxx 会为您处理好这件事。

检查您没有将 libpqxx 库安装在不同的位置，例如 /usr/lib、/usr/local 和 /usr/local/pgsql/lib。

于 2011-03-13T19:40:43.983 回答