推荐9个常用的php代码

连接数据库：

$servername = "localhost";$username = "username";$password = "password";$dbname = "database";$conn = new mysqli($servername, $username, $password, $dbname);if ($conn->connect_error) {die("连接失败: " . $conn->connect_error);}

查询数据库：

$sql = "SELECT * FROM table_name";$result = $conn->query($sql);if ($result->num_rows > 0) {while($row = $result->fetch_assoc()) {echo "字段1: " . $row["column1"]. " - 字段2: " . $row["column2"]. "";}} else {echo "0 结果";}

插入数据到数据库：

$sql = "INSERT INTO table_name (column1, column2, column3)VALUES ('value1', 'value2', 'value3')";if ($conn->query($sql) === TRUE) {echo "新记录插入成功";} else {echo "Error: " . $sql . "" . $conn->error;}

更新数据库中的数据：

$sql = "UPDATE table_name SET column1='new_value' WHERE condition";if ($conn->query($sql) === TRUE) {echo "记录更新成功";} else {echo "Error: " . $sql . "" . $conn->error;}

删除数据库中的数据：

$sql = "DELETE FROM table_name WHERE condition";if ($conn->query($sql) === TRUE) {echo "记录删除成功";} else {echo "Error: " . $sql . "" . $conn->error;}

获取当前日期和时间：

$currentDateTime = date('Y-m-d H:i:s');echo $currentDateTime;

获取客户端IP地址：

$ip = $_SERVER['REMOTE_ADDR'];echo $ip;

文件上传：

$target_dir = "uploads/";$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_file)) {echo "文件上传成功";} else {echo "文件上传失败";}

发送电子邮件：

$to = "recipient@example.com";$subject = "邮件主题";$message = "邮件内容";$headers = "From: sender@example.com" . "\r\n" ."Reply-To: sender@example.com" . "\r\n" ."X-Mailer: PHP/" . phpversion();if (mail($to, $subject, $message, $headers)) {echo "邮件发送成功";} else {echo "邮件发送失败";}