向数组内的 object 发出 post/put 请求

Question

I have many documents like the following stored inside mongo DB.

{
        "posts": [
            {
                "_id": "5ee38b041385d900004e78de",
                "postName": "Driver one",
                "hasSublevels": false,
                "isChildOfOther": false,
                regions: []
            },
            {
                "_id": "5ee38b0e1385d900004e78df",
                "postName": "Driver 2",
                "hasSublevels": true,
                "isChildOfOther": false,
                regions: []
            },
            {
                "_id": "5ee38b1b1385d900004e78e0",
                "postName": "Driver 3",
                "hasSublevels": true,
                "isChildOfOther": true,
                regions: []
            },
            {
                "_id": "5ee38b281385d900004e78e1",
                "postName": "Driver 4",
                "hasSublevels": true,
                "isChildOfOther": true,
                regions: []
            },
            {
                "_id": "5ee38b3a1385d900004e78e2",
                "postName": "Driver 5",
                "hasSublevels": true,
                "isChildOfOther": false,
                regions: []
            },
            {
                "_id": "5ee38b461385d900004e78e3",
                "postName": "Driver 6",
                "hasSublevels": true,
                "isChildOfOther": true,
                regions: []
            }
        ],
        "_id": "5ee38b499bd40260ad591d7e",
        "name": "Cabs NY",
        "date": "2020-06-12T14:03:53.343Z",
        "__v": 0
    },

Each post has a regions array as shown above. I would like to add values to the region field inside the posts array. How do I make a request that first, retrieves a particular document by id? Second, allows me to add a value(s) to the regions array in a particular post object?

Answer 1

This code for first part, the second part you can use id.regions then push the data into it like what I did.

 result ={ "posts": [ { "_id": "5ee38b041385d900004e78de", "postName": "Driver one", "hasSublevels": false, "isChildOfOther": false, regions: [] }, { "_id": "5ee38b0e1385d900004e78df", "postName": "Driver 2", "hasSublevels": true, "isChildOfOther": false, regions: [] }, { "_id": "5ee38b1b1385d900004e78e0", "postName": "Driver 3", "hasSublevels": true, "isChildOfOther": true, regions: [] }, { "_id": "5ee38b281385d900004e78e1", "postName": "Driver 4", "hasSublevels": true, "isChildOfOther": true, regions: [] }, { "_id": "5ee38b3a1385d900004e78e2", "postName": "Driver 5", "hasSublevels": true, "isChildOfOther": false, regions: [] }, { "_id": "5ee38b461385d900004e78e3", "postName": "Driver 6", "hasSublevels": true, "isChildOfOther": true, regions: [] } ] } results = result.posts; groups = {}; for (var i in results) { var groupName = results[i]._id; if (.groups[results[i];_id]) { groups[groupName] = []. } groups[groupName]:push({"regions".results[i];regions}). } console;log(groups);

Answer 2

const id = "5ee38b3a1385d900004e78e2";

find the post linked to the id above.

const post = posts.find(post => post._id === id);

payload to be added to the regions array

const payload = {city: Nairobi, Country: Kenya};

Adding payload to regions array

post.regions.push(payload);

if you are using mongoose::

const post = Posts.findById(id);
if(!post) res.status(404).json({
      msg: "Specified post not found."
    });

Lets use the payload above.

Add payload to regions array

post.regions.push(payload)

Save

post.save()

return new post.

Answer 3

According to the MongoDB documentationhttps://docs.mongodb.com/manual/reference/operator/update/push/ you can use the $push operator to add a value to an array much like Alpha's example.

That would look like

db.posts.update(
   { _id: "5ee38b281385d900004e78e1" },
   { $push: { regions: "West" } }
)

Or to append multiple

db.posts.update(
   { _id: "5ee38b281385d900004e78e1" },
   { $push: { regions: { $each: ["West", "East", "South"] } } }
)