2012-01-15 37 views
1

我有C++代碼來連接並用mysql:CPP-mysql的未定義的引用「的功能」錯誤

#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; 
} 

當我編譯,我得到test.cpp:(.text+0x11): undefined reference to 'mysql_init'mysql_real_connectmysql_error同樣的錯誤。

我已經試過gcc -o test -L/usr/lib/mysql -lmysqlclient test.cpp,但這給我以下錯誤:

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. 

我檢查mysql.hmysql_real_connect的定義是:

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); 

我沒有問題,當我做不使用這些mysql函數。是否有另一個選擇來解決這個問題?

回答

2

您需要編譯並鏈接C++代碼與g++而不是gcc。否則,C++標準庫將無法正確鏈接。

+0

so g ++ -o test -L/usr/lib/mysql -lmysqlclient test.cpp實際上是解決這個問題的方法嗎? – 2012-01-15 13:02:53

+0

對於未定義的符號,是的。 (儘管你應該在'test.cpp'後面加上'-lmysqlclient'作爲該行的結尾。) – Mat 2012-01-15 13:03:45