C/C++操作MySQL API调用

记录下MySQL的C语言API的使用

1、Linux环境，操作系统是ubuntu

执行：sudo apt-get install libmysqlclient-dev

这样系统默认头文件路径(/usr/include)下就会多了一个mysql的文件夹，里面就是API头文件；

动态库路径/usr/lib/x86_64-linux-gnu/libmysqlclient.so。

2、Windows环境，操作系统win10

本地安装MySQL(官网有下载)，vs新建工程，从安装目录(C:\Program Files (x86)\MySQL\MySQL Server 5.7)拷贝出include、lib两个文件夹到vs工程文件夹，

包含静态库通过方法：

#pragma comment(lib,"lib/libmysql.lib")
#pragma comment(lib,"lib/mysqlclient.lib")

包含动态库方法： 将libmysql.dll拷贝到生成exe的目录中

vs程序实例如下，mysql服务器是在linux服务器上，通过远程网络连接：

#include <winsock.h>
#include "include/mysql.h"
#include <iostream>
#include <string>
#pragma comment(lib,"lib/libmysql.lib")
#pragma comment(lib,"lib/mysqlclient.lib")
using namespace std;

int main()
{
    cout << __FUNCTION__ << " is called." << endl;
    string sql;
    MYSQL mysql;
    try
    {    
        mysql_init(&mysql);    
        // 连接远程数据库
        if (NULL == mysql_real_connect(&mysql, "192.168.1.102", "root", "hongrui123", "mysql", 3306, NULL, 0))
        {    
            cout << __LINE__ << mysql_error(&mysql) << mysql_errno(&mysql) << endl;
            throw - 1;
        }

        //创建数据库hr_1
        sql = "create database if not exists hr_1;";
        if (mysql_query(&mysql, sql.c_str()))
        {
            cout << "line: " << __LINE__ << ";"<< mysql_error(&mysql) << mysql_errno(&mysql) << endl;
            throw - 1;
        }
        
        //进入数据库hr_1
        sql = "use hr_1;";
        if (mysql_query(&mysql, sql.c_str()))
        {
            cout << "line: " << __LINE__ << ";" << mysql_error(&mysql) << mysql_errno(&mysql) << endl;
            throw - 1;
        }

        //创建表hr_tbl
        sql = "create table if not exists `hr_tbl`(\
            `id` INT auto_increment,\
            `title` VARCHAR(100),\
            `name` VARCHAR(100),\
            primary key(id))\
            default charset = utf8;";
        if (mysql_query(&mysql, sql.c_str()))
        {
            cout << "line: " << __LINE__ << ";" << mysql_error(&mysql) << mysql_errno(&mysql) << endl;
            throw - 1;
        }

        //插入数据,事务
        sql = "begin;";
        mysql_query(&mysql, sql.c_str());
        sql = "insert into hr_tbl(title,name)\
                values (\"hong\",\"rui\");";
        if (mysql_query(&mysql, sql.c_str()))
        {
            cout << "line: " << __LINE__ << ";" << mysql_error(&mysql) << mysql_errno(&mysql) << endl;
        }
        sql = "commit;";
        mysql_query(&mysql, sql.c_str());
        //更新数据
        sql = "update hr_tbl set title = 'huang' where id < 3;";
        if (mysql_query(&mysql, sql.c_str()))
        {
            cout << "line: " << __LINE__ << ";" << mysql_error(&mysql) << mysql_errno(&mysql) << endl;
        }
        
        //删除数据
        sql = "delete from hr_tbl where id > 4;";
        if (mysql_query(&mysql, sql.c_str()))
        {
            cout << "line: " << __LINE__ << ";" << mysql_error(&mysql) << mysql_errno(&mysql) << endl;
        }

        //查询数据
        sql = "select * from hr_tbl;";
        if (mysql_query(&mysql, sql.c_str()))
        {
            cout << "line: " << __LINE__ << ";" << mysql_error(&mysql) << mysql_errno(&mysql) << endl;
            throw -1;
        }
        else
        {
            //读取检索的结果
            MYSQL_RES *result = mysql_use_result(&mysql);
            if (result != NULL)
            {
                MYSQL_ROW row;
                int num_fields = mysql_num_fields(result);//每一行的字段数量
                while (row = mysql_fetch_row(result))
                {
                    if (row == NULL)
                    {
                        break;
                    }
                    else
                    {
                        for (int i= 0; i < num_fields; ++i)
                        {
                            cout << row[i]<<" ";
                        }
                        cout << endl;
                    }
                }
            }
            mysql_free_result(result);
        }
    }
    catch (...)
    {
        cout << "MySQL operation is error!" << endl;
    }

    mysql_close(&mysql);
    system("pause");
    return 0;
}