PHP에서 mysql 데이터베이스의 데이터를 삭제하는 방법

<?php
//连接到数据库
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

//创建连接对象
$conn = new mysqli($servername, $username, $password, $dbname);

//检查连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

//编写删除数据的SQL语句
$sql = "DELETE FROM myTable WHERE id=1";

//执行SQL语句
if ($conn->query($sql) === TRUE) {
    echo "数据删除成功";
} else {
    echo "删除失败: " . $conn->error;
}

//关闭连接
$conn->close();
?>

<?php
//连接到数据库
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

//创建连接对象
$conn = new mysqli($servername, $username, $password, $dbname);

//检查连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

//获取用户输入的数据
$id = $_POST[&#39;id&#39;];

//使用mysql_real_escape_string()函数转义用户输入的数据
$id = mysql_real_escape_string($id);

//编写删除数据的SQL语句
$sql = "DELETE FROM myTable WHERE id=&#39;$id&#39;";

//执行SQL语句
if ($conn->query($sql) === TRUE) {
    echo "数据删除成功";
} else {
    echo "删除失败: " . $conn->error;
}

//关闭连接
$conn->close();
?>

<?php
//连接到数据库
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

//创建连接对象
$conn = new mysqli($servername, $username, $password, $dbname);

//检查连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

//开启事务
$conn->begin_transaction();

//编写删除数据的SQL语句
$sql1 = "DELETE FROM myTable WHERE id=1;";
$sql2 = "DELETE FROM myTable1 WHERE id=2;";

//删除数据
if ($conn->query($sql1) === TRUE && $conn->query($sql2) === TRUE) {
    //提交事务
    $conn->commit();
    echo "所有数据删除成功";
} else {
    echo "删除失败: " . $conn->error;
    //回滚事务，撤销删除操作
    $conn->rollback();
}

//关闭连接
$conn->close();
?>