PHP를 사용하여 CMS 시스템의 분류 관리 기능을 구현하는 방법

<?php
function connectDB() {
  $servername = "localhost";
  $username = "root";
  $password = "";
  $dbname = "categories";

  $conn = new mysqli($servername, $username, $password, $dbname);

  if ($conn->connect_error) {
    die("连接数据库失败: " . $conn->connect_error);
  }

  return $conn;
}
?>

<?php
function addCategory($name, $parentId) {
  $conn = connectDB();

  $sql = "INSERT INTO categories (name, parent_id) VALUES ('$name', '$parentId')";

  if ($conn->query($sql) === TRUE) {
    echo "分类添加成功";
  } else {
    echo "分类添加失败: " . $conn->error;
  }

  $conn->close();
}
?>

<?php
function editCategory($categoryId, $name, $parentId) {
  $conn = connectDB();

  $sql = "UPDATE categories SET name='$name', parent_id='$parentId' WHERE id='$categoryId'";

  if ($conn->query($sql) === TRUE) {
    echo "分类编辑成功";
  } else {
    echo "分类编辑失败: " . $conn->error;
  }

  $conn->close();
}
?>

<?php
function deleteCategory($categoryId) {
  $conn = connectDB();

  $sql = "DELETE FROM categories WHERE id='$categoryId'";

  if ($conn->query($sql) === TRUE) {
    echo "分类删除成功";
  } else {
    echo "分类删除失败: " . $conn->error;
  }

  $conn->close();
}
?>

<?php
function getCategories() {
  $conn = connectDB();

  $sql = "SELECT id, name, parent_id FROM categories";
  $result = $conn->query($sql);

  if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
      echo "分类ID: " . $row["id"]. " - 名称: " . $row["name"]. " - 父级分类ID: " . $row["parent_id"]. "<br>";
    }
  } else {
    echo "暂无分类";
  }

  $conn->close();
}
?>