C++连接MYSQL数据库

#include <iostream>
#include <cstdlib>
#include <cstddef>
#include <string>
#include <vector>
#include <WinSock2.h>
#include <mysql.h>
#pragma  comment(lib,"libmysql")
using namespace std;

int main(){

    const char *host = "localhost";
    const char *user = "root";
    const char *upwd = "root";
    const char *dbs = "test";
    unsigned int port = 3306;


    MYSQL mydata;

    if(0==mysql_library_init(0,NULL,NULL)){
        cout<<"mysql_library_init() successed!!"<<endl;
    }else{
        cout<<"mysql_library_init() failed!!"<<endl;
        return -1;
    }

    //初始化数据结构
    if(NULL != mysql_init(&mydata)){
        cout<<"初始化数据结构成功！"<<endl;
    }else{
        cout<<"初始化数据结构失败"<<endl;
        return -1;
    }

    //设置数据库编码类型
    if(0==mysql_options(&mydata,MYSQL_SET_CHARSET_NAME,"utf8")){
        cout<<"设置数据库编码类型成功！"<<endl;
    }else{
        cout<<"设置数据库编码类型失败！"<<endl;
        return -1;
    }

    //连接数据库
    if(NULL != mysql_real_connect(&mydata,host,user,upwd,dbs,port,NULL,0)){
        cout<<"数据库连接成功了！"<<endl;
    }else{
        cout<<"数据库连接失败了！！"<<endl;
        return -1;
    }

    //插入数据
    //string sqlstr;
    //sqlstr="INSERT INTO user(`username`, `password`) VALUES ('test', 'test123');";
    //if(0==mysql_query(&mydata,sqlstr.c_str())){
    //    cout<<"插入数据成功"<<endl;
    //}else{
    //    cout<<"插入数据失败了！！"<<endl;
    //}

    string sqlstr_select = " select * from user;";
    //显示查询结果
    MYSQL_RES *result=NULL;
    if(0==mysql_query(&mydata,sqlstr_select.c_str())){
        cout<<"查询成功！"<<endl;

        //一次性取得数据集
        result =mysql_store_result(&mydata);

        //取得并打印行数
        my_ulonglong rowcount = mysql_num_rows(result);
        cout << "row count: " << rowcount << endl;

        //取得并打印各字段的名称
        unsigned int fieldcount = mysql_num_fields(result);
         MYSQL_FIELD *field = NULL;

         for (unsigned int i = 0; i < fieldcount; i++) {
             field = mysql_fetch_field_direct(result, i);
             cout << field->name << "\t\t";
         }
         cout << endl;

         ////打印各行
         //MYSQL_ROW row = NULL;
         //row = mysql_fetch_row(result);
         //while (NULL != row) {
            // for (int i = 0; i < fieldcount; i++) {
            //     cout << row[i] << "\t\t";
            // }
            // cout << endl;
            // row = mysql_fetch_row(result);
         //}


    }else{
        cout << "mysql_query() select data failed" << endl;
        mysql_close(&mydata);
        return -1;
    }




    mysql_close(&mydata);
    mysql_library_end();
    return 0;
}