用PHP开发的商城购买限额与折扣设置策略分析

CREATE TABLE product (
  id INT PRIMARY KEY,
  name VARCHAR(255),
  price DECIMAL(10, 2)
);

CREATE TABLE cart (
  id INT PRIMARY KEY,
  user_id INT,
  product_id INT,
  quantity INT,
  FOREIGN KEY(user_id) REFERENCES user(id),
  FOREIGN KEY(product_id) REFERENCES product(id)
);

CREATE TABLE user (
  id INT PRIMARY KEY,
  username VARCHAR(255)
);

CREATE TABLE purchase_limit (
  id INT PRIMARY KEY,
  limit_amount DECIMAL(10, 2),
  discount DECIMAL(10, 2)
);

function getPurchaseLimits() {
  $purchaseLimits = array();

  // 连接数据库
  $conn = mysqli_connect("localhost", "username", "password", "database");

  // 查询购买限额与折扣设置信息
  $query = "SELECT * FROM purchase_limit";
  $result = mysqli_query($conn, $query);

  // 将查询结果存入数组
  while ($row = mysqli_fetch_assoc($result)) {
    $purchaseLimits[] = $row;
  }

  // 关闭数据库连接
  mysqli_close($conn);

  // 返回购买限额与折扣设置信息
  return $purchaseLimits;
}

function calculateTotalAmount($user_id) {
  // 连接数据库
  $conn = mysqli_connect("localhost", "username", "password", "database");

  // 查询购物车中的商品信息
  $query = "SELECT SUM(product.price * cart.quantity) AS total_amount
            FROM cart
            INNER JOIN product ON cart.product_id = product.id
            WHERE cart.user_id = " . $user_id;
  $result = mysqli_query($conn, $query);
  $row = mysqli_fetch_assoc($result);
  $totalAmount = $row['total_amount'];

  // 查询购买限额与折扣设置信息
  $purchaseLimits = getPurchaseLimits();

  // 遍历购买限额与折扣设置信息，计算折扣金额
  foreach ($purchaseLimits as $purchaseLimit) {
    if ($totalAmount >= $purchaseLimit['limit_amount']) {
      $discount = $purchaseLimit['discount'];
      break;
    }
  }

  // 计算折扣金额
  $discountAmount = $totalAmount * $discount;

  // 关闭数据库连接
  mysqli_close($conn);

  // 返回折扣金额
  return $discountAmount;
}

// 连接数据库
$conn = mysqli_connect("localhost", "username", "password", "database");

// 查询当前用户的购物车信息
$query = "SELECT * FROM cart WHERE user_id = " . $user_id;
$result = mysqli_query($conn, $query);

// 显示购买限额与折扣设置策略
$purchaseLimits = getPurchaseLimits();
foreach ($purchaseLimits as $purchaseLimit) {
  echo "满" . $purchaseLimit['limit_amount'] . "元，折扣" . ($purchaseLimit['discount'] * 100) . "%<br>";
}

// 显示购物车中的商品总金额和折扣金额
$totalAmount = calculateTotalAmount($user_id);
$discountAmount = $totalAmount - $discountAmount;
echo "商品总金额：¥" . $totalAmount . "<br>";
echo "折扣金额：¥" . $discountAmount . "<br>";

// 关闭数据库连接
mysqli_close($conn);