C语言调用数据库

#include 
#include 
#include 
int main()
{
//1、连接服务器
    MYSQL mysql;
    mysql_init(&mysql);
    if (!mysql_real_connect(&mysql,"128.0.47.135","dengjun123","abc123","school",0,NULL,0))
    {
        fprintf(stderr, "Failed to connect to database: Error: %s\n",
                mysql_error(&mysql));
    }
    mysql_query(&mysql, "set names utf8"); //设置编码
//2、CRUD操作(增删改)
    char sql[300] = "insert into student (sno, name) values (1008, '马云')";
    if(mysql_query(&mysql, sql))
    {
        fprintf(stderr, "Failed to connect to database: Error: %s\n",
                mysql_error(&mysql));
    }
    else
    {
        printf("添加学生信息成功！\n");
    }
    //查
    strcpy(sql, "select s.sno, s.name, sex, phone, c.name, grade from student s, course c, score sc where s.sno=sc.sno and c.cno=sc.cno and c.name='C语言程序设计' and grade>60 order by grade desc, sex desc limit 3");
    if(mysql_query(&mysql, sql))//查询
    {
        fprintf(stderr, "Failed to select: Error: %s\n",
                mysql_error(&mysql));
    }
    else
    {
        MYSQL_RES* res = NULL;//从堆区申请空间保存一行查询内容

        res = mysql_store_result(&mysql);

        if(res != NULL)
        {
            MYSQL_ROW row;
            unsigned int num_fields;//一行由多个字段组成
            unsigned int i;
            num_fields = mysql_num_fields(res);
            while ((row = mysql_fetch_row(res)))//依次输出每行
            {
                for(i = 0; i < num_fields; i++)
                {
                    printf("%s ", row[i]);//依次输出每行的每个字段（列）
                }
                printf("\n");
            }
            mysql_free_result(res);//释放堆区空间
        }
        else
        {
            //失败
            printf("show failed\n");
        }
    }
//3、关闭
    mysql_close(&mysql);
    return 0;
}