php 面向對象的方式訪問數據庫

時間 2020-07-07

原文原文鏈接

<body>
<?php

//面向對象的方式訪問數據庫

//造對象
$db = new MySQLi("localhost","root","123","mydb");

//判斷鏈接是否出錯
/*if(mysqli_connect_error())
{
    echo "鏈接失敗！";
    exit;
}*/

!mysqli_connect_error() or die("鏈接失敗！");

//寫SQL語句
$sql = "insert into Info values('p010','張三',true,'n002','1988-2-3')";

//執行SQL語句，查詢語句返回結果集對象，其餘語句返回true或false
$result = $db->query($sql);

//從結果集對象中讀取數據
//$attr = $result->fetch_all(MYSQLI_BOTH); //以二維數組的方式返回全部數據
//$attr = $result->fetch_array(); //返回當前指針指向的這條數據
//$attr = $result->fetch_assoc(); //返回當前指針指向的這條數據（關聯數組）
//$attr = $result->fetch_object(); //返回對象
//$attr = $result->fetch_row(); //返回索引數組
//var_dump($attr);
/*
while($attr = $result->fetch_row())  //經過循環返回全部一維數組，另外能夠在外面定義一個空數組，把循環出來的數經過array_push方法加到空數組中，輸出一個2維數組，等同於fetch_all();
{
    var_dump($attr);
}*/

//var_dump($result);



?>
</body>

View Code

例子php

登錄界面mysql

<body>
<h1>登陸</h1>
<form action="dlchuli.php" method="post">
<div>用戶名：<input type="text" name="uid" /></div>
<div>密碼：<input type="text" name="pwd" /></div>
<input type="submit" value="登陸" />
</form>
</body>

View Code

<?php
$uid = $_POST["uid"];
$pwd = $_POST["pwd"];

//造對象
$db = new MySQLi("localhost","root","123","mydb");
//判斷是否出錯
!mysqli_connect_error() or die("鏈接失敗！");
//寫SQL語句
//容易被SQL注入攻擊,不安全
//$sql = "select count(*) from Users where Uid = '{$uid}' and Pwd='{$pwd}'";


$sql = "select Pwd from Users where Uid='{$uid}'";

//執行SQL語句
$result = $db->query($sql);

//取數據
$attr = $result->fetch_row();

if($attr[0] == $pwd)
{
    header("location:main.php");
}
else
{
    echo "登陸失敗！";

View Code

註冊界面sql

<body>
<form action="zcchuli.php" method="post">
<div>用戶名：<input type="text" name="uid" /></div>
<div>密碼：<input type="text" name="pwd" /></div>
<div>姓名：<input type="text" name="name" /></div>
<div>性別：<input type="radio" value="1" name="sex" />男 <input type="radio" value="0" name="sex" />女</div>
<div>生日：<input type="text" name="birthday" /></div>
<input type="submit" value="註冊" />
</form>
</body>

View Code

<?php
$uid = $_POST["uid"];
$pwd = $_POST["pwd"];
$name = $_POST["name"];
$sex = $_POST["sex"];
$birthday = $_POST["birthday"];

$s = $sex==1?true:false;

//造對象
$db = new MySQLi("localhost","root","123","mydb");

//判斷是否出錯
!mysqli_connect_error() or die("鏈接失敗！");

//寫SQL語句
$sql = "insert into Users values('{$uid}','{$pwd}','{$name}',{$s},'{$birthday}',0)";

//執行SQL語句
$result = $db->query($sql);

if($result)
{
    header("location:zhuce.php");
}
else
{
    echo "註冊失敗！";
}