如何在php

Question

此代码用于检查slug或执行插入操作时是否存在于数据库中的任何值。

<?php
    if($_SERVER['REQUEST_METHOD'] === 'POST') {
        $slug =$_POST['slug'];
        $title =$_POST['title'];
        $description= $_POST['description'];
        //$created_date=$_POST['created_date'];
        // $updated_date = $_POST['updated_date'];
        $status = $_POST['status'];
        $sql = "INSERT INTO Pages SET slug='$slug', title='$title', description='$description', status='$status'"; // query to insert into database


        $result = $con->query($sql);
        if ($result->num_rows > 0) { //checking the db table*emphasized text*
            $data = $result->fetch_assoc($);
            echo "Slug already used"; //duplicate slug is existed.
            die;
        }
        else {
            echo "No slug used"; //when no similar slug is used
            die;
        }
        header("Location: pages.php?success=Record added successfully.");
        die;
    }
?>