Mongoose：如何筛选多文档中子文档并返回含父信息的普通数组

我开发了一款电商应用，其中产品（Product）包含多个变体（variant），变体存储在每个Product对象的数组中，原始数据结构如下：

[
    {
      "title": "Test",
      "description": "test description",
      "variants": [
        {
           "id": 1,
           "color": "red",
           "size": "L",
           "price": 500
        },
        {
           "id": 2,
           "color": "red",
           "size": "M",
           "price": 500
        },
        {
           "id": 3,
           "color": "red",
           "size": "S",
           "price": 500
        }    
      ]
    }
]

请问能否通过变体ID进行筛选，返回忽略父产品来源但包含父产品详情的普通变体数组？目标数据结构如下：

[
        {
           "id": 1,
           "color": "red",
           "size": "L",
           "price": 500,
           "parent": {
             "title": "Test",
             "description": "test description"
           }
        },
        {
           "id": 2,
           "color": "red",
           "size": "M",
           "price": 500,
           "parent": {
             "title": "Test",
             "description": "test description"
           }
        },
        {
           "id": 3,
           "color": "red",
           "size": "S",
           "price": 500,
           "parent": {
             "title": "Test",
             "description": "test description"
           }
        },
        {
           "id": 4,
           "color": "orange",
           "size": "S",
           "price": 500,
           "parent": {
             "title": "Test 2",
             "description": "test description 2"
           }
        }  
] 

当然可以实现，以下是具体的实现思路和代码示例：

核心步骤 #

1. 遍历所有产品，将每个产品的变体展开，同时为每个变体添加包含父产品关键信息的parent字段，形成全量变体数组
2. 根据目标变体ID列表，从全量数组中筛选出匹配的变体

JavaScript实现示例 #

// 模拟原始产品数据
const products = [
  {
    title: "Test",
    description: "test description",
    variants: [
      { id: 1, color: "red", size: "L", price: 500 },
      { id: 2, color: "red", size: "M", price: 500 },
      { id: 3, color: "red", size: "S", price: 500 }
    ]
  },
  {
    title: "Test 2",
    description: "test description 2",
    variants: [
      { id: 4, color: "orange", size: "S", price: 500 }
    ]
  }
];

// 需要筛选的目标变体ID
const targetIds = [2, 4];

// 生成带父产品信息的全量变体数组
const allVariantsWithParent = products.flatMap(product => {
  const parentData = {
    title: product.title,
    description: product.description
    // 可根据业务需求添加更多父产品字段，如id、分类等
  };
  return product.variants.map(variant => ({ ...variant, parent: parentData }));
});

// 根据ID筛选目标变体
const result = allVariantsWithParent.filter(variant => targetIds.includes(variant.id));

console.log(result);

注意事项 #

• 可根据实际业务需求调整parent字段中包含的父产品信息，避免冗余数据
• 如果变体数量极大，可在遍历过程中直接完成筛选，减少内存占用
• 若使用TypeScript，可定义对应的接口规范数据结构，提升代码健壮性

内容的提问来源于stack exchange，提问作者Tharindu Thisarasinghe