PHP を使用して製品の複数仕様 SKU 機能のコードを記述する方法

CREATE TABLE products (
  id INT(11) PRIMARY KEY AUTO_INCREMENT,
  name VARCHAR(255) NOT NULL,
  price DECIMAL(10,2) NOT NULL,
  stock INT(11) NOT NULL
);

CREATE TABLE skus (
  id INT(11) PRIMARY KEY AUTO_INCREMENT,
  product_id INT(11) NOT NULL,
  attribute VARCHAR(255) NOT NULL,
  value VARCHAR(255) NOT NULL,
  FOREIGN KEY (product_id) REFERENCES products(id)
);

function getAttributes($productId) {
  $sql = "SELECT DISTINCT attribute FROM skus WHERE product_id = $productId";
  $result = mysqli_query($conn, $sql);
  $attributes = array();

  if (mysqli_num_rows($result) > 0) {
    while ($row = mysqli_fetch_assoc($result)) {
      $attributes[] = $row['attribute'];
    }
  }

  return $attributes;
}

function getSKU($productId, $selectedAttributes) {
  $sql = "SELECT * FROM skus WHERE product_id = $productId";
  $result = mysqli_query($conn, $sql);
  $skus = array();

  if (mysqli_num_rows($result) > 0) {
    while ($row = mysqli_fetch_assoc($result)) {
      $skuAttributes = array();
      $skuAttributes[$row['attribute']] = $row['value'];

      if (array_intersect_assoc($selectedAttributes, $skuAttributes) === $selectedAttributes) {
        $skus[] = $row;
      }
    }
  }

  return $skus;
}

$productId = 1;
$selectedAttributes = array(
  'Color' => 'Red',
  'Size' => 'L'
);

$attributes = getAttributes($productId);
$skus = getSKU($productId, $selectedAttributes);

foreach ($attributes as $attribute) {
  echo "<label>$attribute:</label>";
  echo "<select>";

  $attributeValues = array_unique(array_column($skus, 'value', 'attribute'));
  foreach ($attributeValues as $value) {
    echo "<option value="$value">$value</option>";
  }

  echo "</select>";
}

if (!empty($skus)) {
  echo "Price: " . $skus[0]['price'];
  echo "<br>";
  echo "Stock: " . $skus[0]['stock'];
} else {
  echo "No SKU available.";
}