javascript - MongoDB Node.JS 驱动程序 : create, 使用数组追加和更新文档

Question

我希望使用 MongoDB Node.JS 驱动程序实现以下操作，这可以通过最佳方法执行吗？需要三种可能的操作:创建、追加和更新。

1. 创建以下文档。

{
    "_id": "hello_world_cluster",
        "items": [
            {
                "item_name": "my_item_one",
                "first_seen": 1000,
                "last_seen": 1000,
                "logic": true
            }
        ]
}

将新项目追加到数组中。

{
    "_id": "hello_world_cluster",
        "items": [
            {
                "item_name": "my_item_one",
                "first_seen": 1000,
                "last_seen": 1000,
                "logic": true
            },
            {
                "item_name": "my_item_two",
                "first_seen": 2000,
                "last_seen": 2000,
                "logic": true
            },
            {
                "item_name": "my_item_three",
                "first_seen": 3000,
                "last_seen": 3000,
                "logic": true
            }
        ]
}

更新数组中找到的项。

{
    "_id": "hello_world_cluster",
        "items": [
            {
                "item_name": "my_item_one",
                "first_seen": 1000,
                "last_seen": 4000,
                "logic": false
            },
            {
                "item_name": "my_item_two",
                "first_seen": 2000,
                "last_seen": 2000,
                "logic": true
            },
            {
                "item_name": "my_item_three",
                "first_seen": 3000,
                "last_seen": 3000,
                "logic": true
            }
        ]
}

Answer 1

我为您起草了一些示例代码:

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

async function main() {
    /**
     * Connection URI. Update <username>, <password>, and <your-cluster-url> to reflect your cluster.
     */
    const uri = "mongodb+srv://<username>:<password>@<your-cluster-url>/test?retryWrites=true&w=majority";

    /**
     * The Mongo Client you will use to interact with your database
     */
    const client = new MongoClient(uri, { useUnifiedTopology: true });

    try {
        // Connect to the MongoDB cluster
        await client.connect();

        // Make the appropriate DB calls

        // Create a new document
        await createDocument(client);

        // Append new items to the items array
        await appendNewItemsToArray(client);

        // Update items in the items array
        await updateItemsInArray(client);


    } finally {
        // Close the connection to the MongoDB cluster
        await client.close();
    }
}

main().catch(console.error);

async function createDocument(client) {
    const result = await client.db("NameOfYourDb").collection("NameOfYourCollection").insertOne({
        "_id": "UniqueId1",
        "items": [
            {
                "item_name": "my_item_one",
                "first_seen": 1000,
                "last_seen": 1000,
                "logic": true
            }
        ]
    });
    console.log(`New document created with the following id: ${result.insertedId}`);
}

async function appendNewItemsToArray(client) {
    const result = await client.db("NameOfYourDb").collection("NameOfYourCollection").updateOne(
        { "_id": "UniqueId1" },
        {
            $push: {
                items: {
                    $each: [
                        {
                            "item_name": "my_item_two",
                            "first_seen": 2000,
                            "last_seen": 2000,
                            "logic": true
                        },
                        {
                            "item_name": "my_item_three",
                            "first_seen": 3000,
                            "last_seen": 3000,
                            "logic": true
                        }]
                }
            }
        });

    console.log(`${result.matchedCount} document(s) matched the query criteria.`);
    console.log(`${result.modifiedCount} document(s) was/were updated.`);
}

async function updateItemsInArray(client) {
    const result = await client.db("NameOfYourDb").collection("NameOfYourCollection").updateOne(
        { "_id": "UniqueId1", "items.item_name": "my_item_one" },
        { $set: { "items.$.logic": false, "items.$.last_seen": 4000 } }
    );

    console.log(`${result.matchedCount} document(s) matched the query criteria.`);
    console.log(`${result.modifiedCount} document(s) was/were updated.`);
}

需要注意的一件重要事情:集合中的每个文档的 _id 都必须是唯一的。您不必手动创建 _id。如果您在文档中省略 _id，驱动程序将自动为您创建一个。

此代码基于我的博客系列中的代码。一些对您有用的链接:

• https://www.mongodb.com/blog/post/quick-start-nodejs-mongodb--how-to-get-connected-to-your-database
  • https://www.mongodb.com/blog/post/quick-start-nodejs--mongodb--how-to-create-documents
  • https://www.mongodb.com/blog/post/quick-start-nodejs--mongodb--how-to-update-documents

该代码利用了 $push 和 $each 的组合。请参阅https://docs.mongodb.com/manual/reference/operator/update/push/#example-push-each了解更多详细信息。

该代码还利用了位置 $ 运算符。请参阅https://docs.mongodb.com/manual/reference/operator/update/positional/了解更多详细信息。