如何为每个具有不同用户名并能够同时有多个人的用户创建数据库列表？

Question

我正在尝试制作一个应用程序并且它使用数据库，我遇到的问题或墙壁是我一次只能有一个连接，而不是多个连接，否则它会给出错误并且不起作用。我将用户名存储在一个变量中，即var user = "";，一次只能有一个连接。

var user = "";

const userSchema = new mongoose.Schema({
    first_name: String,
    last_name: String,
    email: String,
    password: String,
});

const ItemSchema = new mongoose.Schema({
    person: String,
    date: String,
    loc: String,
    title: String,
    passage: String,
    file: String
});

const User = mongoose.model("User", userSchema);
const Item = mongoose.model("Item", ItemSchema);

const item1 = new Item({
    person: user,
    date: "String",
    loc: "String",
    title: "String",
    passage: "String",
    file: "String"
});

const defaultItems = [item1];

//item1.save();
// user1.save();

app.get("/", function (req, res) {

    res.render("home");

});

app.get("/loading", function (req, res) {

    res.render("loading");

});

app.get("/signup", function (req, res) {

    res.render("signup");

});

app.get("/login", function (req, res) {

    res.render("login");

});

app.get("/workspace", function (req, res) {

    Item.find({ person: user }, function (err, foundItems) {

        if (foundItems.length == 0) {
            Item.insertMany(defaultItems, function (err) {
                if (err) {
                    console.log(err);
                } else {
                    console.log("Added items");
                }
            });
            res.redirect("/workspace");

        } else {
            res.render("workspace", { itemList: foundItems });
        }
    });


});

app.post("/login", function (req, res) {

    const email = req.body.email;
    const password = req.body.password;

    User.findOne({ email: email }, function (err, foundUser) {
        if (err) {
            console.log(err);
        } else {
            if (foundUser) {
                if (foundUser.password == password) {
                    console.log("Loged In");
                    res.redirect("/workspace");
                    user = email;
                }
            }
        }
    });
});

app.post("/signup", function (req, res) {

    const firstName = req.body.firstName;
    const lastName = req.body.lastName;
    const email = req.body.email;
    const password = req.body.password;

    const User1 = mongoose.model("User", userSchema);

    const user2 = new User1({
        first_name: firstName,
        last_name: lastName,
        email: email,
        password: password,
    });

    user2.save();

    user = email;

    console.log("Done");

    res.redirect("/workspace");
});

app.post("/workspace", function (req, res) {

    const date = req.body.input1;
    const location = req.body.input2;
    const title = req.body.input3;
    const passage = req.body.input4;
    const file = req.body.input5;

    const item = new Item({
        person: user,
        date: date,
        loc: location,
        title: title,
        passage: passage,
        file: file
    });

    item.save();

    res.redirect("/workspace");
});

有没有一种方法可以让多人同时连接并使用该应用，并为每个用户使用不同的数据库？

Answer 1

一个粗略的想法。

在建立 MongoDB 连接时，为每个访问者生成一个唯一的 ID，并根据 ID 更改 DB 的名称。请参考以下代码：

const mongoose = require('mongoose');
const uuid     = require('uuid');
const dbName   = uuid();
// connecting to mongo database
mongoose.connect('mongodb://127.0.0.1/' + dbName, { useNewUrlParser: true, useFindAndModify: false ,useUnifiedTopology: true }, function (err) {
    if(err) {
        console.log(err);
    } else {
        console.log('Successfully connected to database.');
    }
});

它将为每个新访问者创建一个新的数据库名称。这可能不是最好的解决方案。