C/C++操作MySQL API調用

記錄下MySQL的C語言API的使用

1、Linux環境，操作系統是ubuntu

執行：sudo apt-get install libmysqlclient-dev

這樣系統默認頭文件路徑(/usr/include)下就會多了一個mysql的文件夾，里面就是API頭文件；

動態庫路徑/usr/lib/x86_64-linux-gnu/libmysqlclient.so。

2、Windows環境，操作系統win10

本地安裝MySQL(官網有下載)，vs新建工程，從安裝目錄(C:\Program Files (x86)\MySQL\MySQL Server 5.7)拷貝出include、lib兩個文件夾到vs工程文件夾，

包含靜態庫通過方法：

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

包含動態庫方法： 將libmysql.dll拷貝到生成exe的目錄中

vs程序實例如下，mysql服務器是在linux服務器上，通過遠程網絡連接：

#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);    
        // 連接遠程數據庫
        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;
        }

        //創建數據庫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;
        }
        
        //進入數據庫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;
        }

        //創建表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;
        }

        //插入數據,事務
        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());
        //更新數據
        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;
        }
        
        //刪除數據
        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;
        }

        //查詢數據
        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
        {
            //讀取檢索的結果
            MYSQL_RES *result = mysql_use_result(&mysql);
            if (result != NULL)
            {
                MYSQL_ROW row;
                int num_fields = mysql_num_fields(result);//每一行的字段數量
                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;
}