Cpp-Mysql 未定义对“函数"错误的引用 [英] Cpp-Mysql undefined reference to 'a function' error

问题描述

我有 C++ 代码可以连接并使用 mysql:

I have c++ code to connect to and use mysql:

#include <iostream>
#include <mysql/mysql.h>

using namespace std;

MYSQL *connection, mysql;
MYSQL_RES *result;
MYSQL_ROW row;
int query_state;

int main() {
mysql_init(&mysql);

connection = mysql_real_connect(&mysql,"localhost","root","pass","cpp_data",0,0,0);
if (connection == NULL) {
cout << mysql_error(&mysql) << endl;
return 1;
}
return 0;
}

当我编译时，我得到 test.cpp:(.text+0x11): undefined reference to 'mysql_init' 和 mysql_real_connect 和 相同的错误mysql_error.

When I compile, I get test.cpp:(.text+0x11): undefined reference to 'mysql_init' and the same error for mysql_real_connect and mysql_error.

我尝试过 gcc -o test -L/usr/lib/mysql -lmysqlclient test.cpp，但这给了我以下错误:

I have tried gcc -o test -L/usr/lib/mysql -lmysqlclient test.cpp, but this give me the following errors:

test.cpp:(.text+0x7a): undefined reference to `std::cout'
test.cpp:(.text+0x7f): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)'
test.cpp:(.text+0x87): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&)' etc.

我查了mysql.h，mysql_real_connect的定义是:

MYSQL *     STDCALL mysql_real_connect(MYSQL *mysql, const char *host,
                       const char *user,
                       const char *passwd,
                       const char *db,
                       unsigned int port,
                       const char *unix_socket,
                       unsigned long clientflag);

我不用这些mysql函数就没有问题.有没有其他方法可以解决这个问题?

I have no problem when I don't use these mysql functions. Is there another option to solve this problem?

推荐答案

您需要使用 g++ 而不是 gcc 来编译和链接 C++ 代码.否则 C++ 标准库将无法正确链接.

You need to compile and link C++ code with g++, not gcc. Otherwise the C++ standard libraries will not get linked properly.

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