如何使用.addField遍历数组

const { MongoClient } = require('mongodb');

async function run() {
  const uri = "your_mongodb_connection_string";
  const client = new MongoClient(uri);

  try {
    await client.connect();
    const database = client.db('your_database_name');
    const collection = database.collection('your_collection_name');

    const pipeline = [
      {
        $addFields: {
          newArrayField: {
            $map: {
              input: "$arrayField", // 假设你的文档中有一个名为 arrayField 的数组字段
              as: "item",
              in: {
                $multiply: ["$$item", 2] // 对数组中的每个元素执行操作，例如乘以 2
              }
            }
          }
        }
      },
      {
        $project: {
          _id: 0,
          newArrayField: 1
        }
      }
    ];

    const result = await collection.aggregate(pipeline).toArray();
    console.log(result);
  } finally {
    await client.close();
  }
}

run().catch(console.dir);