怎样在C++中调用MYSQL数据库中的数据

1、用CAPI连接MySQL数据库有两个步骤：
1）初始化一个连接句柄
2）建立连接
所用到的函数如下：
MYSQL *mysql_init(MYSQL *connection); // 初始化连接句柄
//成功返回MySQL结构指针，失败返回NULL

MYSQL *mysql_real_connect(MYSQL *connection,
const char *server_host,
const char *sql_user_name,
const char *sql_password,
const char *db_name,
unsigned int port_number,
const char *unix_socket_name,
unsigned int flags); //建立连接
//成功返回MySQL结构指针，失败返回NULL
以下是完整实例：

#include
#include
#include
#include

using namespace std;

void mysql_err_function(MYSQL * connection);

int main()
{
//freopen("input.txt","r",stdin);

MYSQL * connection;
connection = mysql_init(NULL);

if (!connection)
{
cout << "mysql_init failed!" << endl;

exit(-1);
}

if (!mysql_real_connect(connection,"localhost","root","123456","test",0,NULL,0))
{
cout << "Connection To MySQL failed!" << endl;
mysql_err_function(connection);
}

cout << "Connection To MySQL Server is Success..." << endl;

string str;
getline(cin,str);

int res = 0;
int affected_count = 0;
while (str != "close" && str != "" && !res)
{
res = mysql_query(connection,str.c_str());

affected_count += mysql_affected_rows(connection);

if (res)
{
if (mysql_errno(connection))
{
cout << "Error " << mysql_errno(connection) << " : "
<< mysql_error(connection) << '\n' << endl;
break;
}
}
getline(cin,str);
}

cout << "Have affected " << affected_count << " rows!" << endl;

mysql_close(connection);
cout << "Connection To MySQL Server is closed..." << endl;

return 0;
}

void mysql_err_function(MYSQL * connection)
{
if (mysql_errno(connection))
{
cout << "Error " << mysql_errno(connection) << " : "
<< mysql_error(connection) << endl;

exit(-1);
}
}