C++ -連線 php 與 MySQL 資料庫

這篇文章將介紹如何讓 C++ 連線 php 網頁，再透過 php 網頁去取得資料庫的資料。

環境
windows 11 64bit
Visual Studio 2022
遠端主機 cloudways
MariaDB 10.4
php 7.4

準備主程式

#include <iostream>
#include <fstream>
#include <ostream>
#include <cstdlib>
#include <string>
#include <windows.h>
#include <wininet.h> 
using namespace std;

#pragma comment(lib,"Wininet.lib")

const int BUF_SIZE = 1024;
const int URL_SIZE = 1024;

void Download01();
void Download02();
void Download03();

int main()
{
    //Download01(); //傳遞簡單字串和數字參數並回傳
    //Download02(); //取得 MySQL 資料庫資料
    //Download03(); //取得 MySQL 資料庫資料，並存在文字檔裡

    system("pause");
    return 0;
}

1. 連線 php 網頁-傳遞簡單字串和數字參數並回傳

php 程式碼 – cpptest0203.php

<?php
	$userName = $_GET["name"];
	$id = $_GET["id"];
		
	echo $userName.$userName."#".$id;
?>

C++ 程式碼

void Download01()
{
    cout << "測試連線 php 網頁-傳遞簡單字串和數字參數並回傳" << endl;

    char szUrl[1024] = "";
    char szName[128] = "Harry";
    int nID = 1;
    char szUrl02[1024] = "http://localhost/cpptest0203.php?name=%s&id=%d";

    sprintf_s(szUrl, 1024, szUrl02, szName, nID);

    char szBuff[BUF_SIZE] = "";
    HINTERNET hUrl, hInet;
    DWORD rcv, total = 0;

    if (InternetAttemptConnect(0) != ERROR_SUCCESS)
    {
        cout << "Internet connect failed." << endl;
        return;
    }

    hInet = InternetOpen(0, INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, NULL);
    if (hInet == NULL)
    {
        cout << "Internet open failed." << endl;
        return;
    }

    hUrl = InternetOpenUrlA(hInet, szUrl, 0, 0, INTERNET_FLAG_NO_CACHE_WRITE, 0);
    if (hUrl == NULL)
    {
        cout << "Internet open url failed." << endl;
        InternetCloseHandle(hInet);
        return;
    }

    do
    {
        InternetReadFile(hUrl, &szBuff, BUF_SIZE, &rcv);
        total += rcv;
    } while (rcv > 0);

    cout << "receive " << total << " byte." << endl;

    szBuff[total] = '\0';

    cout << szBuff << endl;

    InternetCloseHandle(hUrl);
    InternetCloseHandle(hInet);
}

執行結果

2. 連線 php 網頁-取得 MySQL 資料庫資料

建立 MySQL 資料表

-- ----------------------------
-- Table structure for test01
-- ----------------------------
DROP TABLE IF EXISTS `test01`;
CREATE TABLE `test01`  (
  `id` int(11) NOT NULL,
  `int_test` int(11) NOT NULL,
  `char_test` char(20) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL,
  `varchar_test` varchar(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL,
  `text_test` text CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_unicode_ci ROW_FORMAT = Compact;

-- ----------------------------
-- Records of test01
-- ----------------------------
INSERT INTO `test01` VALUES (1, 10, 'a', 'Harry Potter', 'The novels chronicle the lives of a young wizard, Harry Potter, whom are students at Hogwarts School of Witchcraft and Wizardry.');
INSERT INTO `test01` VALUES (2, 20, 'b', '哈利波特', '是一部兒童奇幻文學系列小說，描寫主角哈利波特在霍格華茲魔法學校7年學習生活中的冒險故事。');
INSERT INTO `test01` VALUES (3, 30, 'c', 'ハリー・ポッター', '1990年代のイギリスを舞台に、魔法使いの少年ハリー・ポッターの学校生活。');

SET FOREIGN_KEY_CHECKS = 1;

php 程式碼 – cpptest0101.php

<?php
	// 建立MySQL的資料庫連接 
	$host = "localhost";
	$dbuser = "user";
	$dbpassword = "password";
	$dbname = "database";
	
	$link = mysqli_connect($host,$dbuser,$dbpassword,$dbname);
	if ( !$link ) 
	{
		echo "不正確連接資料庫 " . mysqli_connect_error();
		echo "<br>";
		exit();
	}
	
	mysqli_query($link, "SET NAMES utf8");
	mysqli_query($link, "SET CHARACTER_SET_database= utf8");
	mysqli_query($link, "SET CHARACTER_SET_CLIENT= utf8");
	mysqli_query($link, "SET CHARACTER_SET_RESULTS= utf8");

	$sql = "select * from test01";
	
	$result = mysqli_query($link, $sql);
	
	if (!$result) 
	{
		echo "{$sql} 語法執行失敗，錯誤訊息 " . mysqli_error($link);
		echo "<br>";
		mysqli_close($link);  // 關閉資料庫連接
		exit();
	}
	
	if (mysqli_num_rows($result)<=0)
	{
		echo "沒有資料";
		echo "<br>";
		mysqli_close($link);  // 關閉資料庫連接
		exit();
	}
	
	while($array = mysqli_fetch_array($result))
	{
		echo $array["int_test"]."#";
		echo $array["varchar_test"]."#";
	}
	
	mysqli_free_result($result);
	
	mysqli_close($link);  // 關閉資料庫連接
	
?>

C++ 程式碼

void Download02()
{
    cout << "測試連線 php 網頁-取得 MySQL 資料庫資料" << endl;

    char szBuff[BUF_SIZE] = "";
    char szUrl[1024] = "http://localhost/cpptest0101.php";
    HINTERNET hUrl, hInet;
    DWORD rcv, total = 0;

    if (InternetAttemptConnect(0) != ERROR_SUCCESS)
    {
        cout << "Internet connect failed." << endl;
        return;
    }

    hInet = InternetOpen(0, INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, NULL);
    if (hInet == NULL)
    {
        cout << "Internet open failed." << endl;
        return;
    }

    hUrl = InternetOpenUrlA(hInet, szUrl, 0, 0, INTERNET_FLAG_NO_CACHE_WRITE, 0);
    if (hUrl == NULL)
    {
        cout << "Internet open url failed." << endl;
        InternetCloseHandle(hInet);
        return;
    }

    do
    {
        InternetReadFile(hUrl, &szBuff, BUF_SIZE, &rcv);
        total += rcv;
    } while (rcv > 0);

    cout << "receive " << total << " byte." << endl;

    szBuff[total] = '\0';

    cout <<szBuff<< endl;   //收到的檔案是 utf-8 字串，直接印出會是亂碼

    //把 utf-8 字串轉成 unicode 並印出，hkstr 是我自己寫的字串轉換函式
    wchar_t szUni[1024] = L"";
    hkstr::UTF8ToUnicode(szUni, szBuff);
    hkstr::PrintfUnicode(L"%s\n", szUni);

    InternetCloseHandle(hUrl);
    InternetCloseHandle(hInet);
}

執行結果

3. 連線 php 網頁-取得 MySQL 資料庫資料並存進文字檔

C++ 程式碼

void Download03()
{
    cout << "測試連線 php 網頁-取得 MySQL 資料庫資料，並存在文字檔裡" << endl;

    ofstream output("test.txt");

    char szBuff[BUF_SIZE] = "";
    char szUrl[1024] = "http://localhost/cpptest0101.php";
    HINTERNET hUrl, hInet;
    DWORD rcv, total = 0;

    if (InternetAttemptConnect(0) != ERROR_SUCCESS)
    {
        cout << "Internet connect failed." << endl;
        return;
    }

    hInet = InternetOpen(0, INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, NULL);
    if (hInet == NULL)
    {
        cout << "Internet open failed." << endl;
        return;
    }

    hUrl = InternetOpenUrlA(hInet, szUrl, 0, 0, INTERNET_FLAG_NO_CACHE_WRITE, 0);
    if (hUrl == NULL)
    {
        cout << "Internet open url failed." << endl;
        InternetCloseHandle(hInet);
        return;
    }

    do
    {
        InternetReadFile(hUrl, &szBuff, BUF_SIZE, &rcv);
        output.write(szBuff, rcv);
        total += rcv;
    } while (rcv > 0);

    cout << "receive " << total << " byte." << endl;

    szBuff[total] = '\0';

    output.close();

    InternetCloseHandle(hUrl);
    InternetCloseHandle(hInet);
}

執行結果