我该如何修复（节点：14352）UnhandledPromiseRejectionWarning：MongoError：E11000 重复键错误集合：错误？

Posted 2023-03-07

【中文标题】我该如何修复（节点：14352）UnhandledPromiseRejectionWarning：MongoError：E11000 重复键错误集合：错误？

【英文标题】：How can i fix (node:14352) UnhandledPromiseRejectionWarning: MongoError: E11000 duplicate key error collection: error?

【发布时间】：2021-06-02 20:19:06

【问题描述】：

我正在开发一个使用数据库并使用用户 ID 向用户添加项目的应用程序，用户 ID 是用户名，但是当我尝试添加项目时出现错误，我似乎无法弄清楚如何修理它。这是错误：

(node:14352) UnhandledPromiseRejectionWarning: MongoError: E11000 duplicate key error collection: sermontracker.items index: _id_ dup key:  _id: "sdfa3asdf2@asdf" 
    at Function.create (C:\Users\Children\Desktop\Web Projects\Sermon_Tracker\node_modules\mongodb\lib\core\error.js:57:12)
    at toError (C:\Users\Children\Desktop\Web Projects\Sermon_Tracker\node_modules\mongodb\lib\utils.js:123:22)
    at C:\Users\Children\Desktop\Web Projects\Sermon_Tracker\node_modules\mongodb\lib\operations\common_functions.js:258:39
    at handler (C:\Users\Children\Desktop\Web Projects\Sermon_Tracker\node_modules\mongodb\lib\core\sdam\topology.js:943:24)
    at C:\Users\Children\Desktop\Web Projects\Sermon_Tracker\node_modules\mongodb\lib\cmap\connection_pool.js:350:13
    at handleOperationResult (C:\Users\Children\Desktop\Web Projects\Sermon_Tracker\node_modules\mongodb\lib\core\sdam\server.js:558:5)
    at MessageStream.messageHandler (C:\Users\Children\Desktop\Web Projects\Sermon_Tracker\node_modules\mongodb\lib\cmap\connection.js:277:5)
    at MessageStream.emit (events.js:315:20)
    at processIncomingData (C:\Users\Children\Desktop\Web Projects\Sermon_Tracker\node_modules\mongodb\lib\cmap\message_stream.js:144:12)
    at MessageStream._write (C:\Users\Children\Desktop\Web Projects\Sermon_Tracker\node_modules\mongodb\lib\cmap\message_stream.js:42:5)
    at doWrite (_stream_writable.js:403:12)
    at writeOrBuffer (_stream_writable.js:387:5)
    at MessageStream.Writable.write (_stream_writable.js:318:11)
    at Socket.ondata (_stream_readable.js:716:22)
    at Socket.emit (events.js:315:20)
    at addChunk (_stream_readable.js:295:12)
(node:14352) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:14352) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

这是错误发生的时间和地点的代码：

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(
        _id: userN,
        date: date,
        loc: location,
        title: title,
        passage: passage,
        file: file
    );

    item.save();

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

这里是完整的代码：

var userN;

var defaultItems = [];

mongoose.connect('mongodb://localhost:27017/sermontracker',
    
        useNewUrlParser: true,
        useUnifiedTopology: true,
        useCreateIndex: true

    
);

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

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


app.post("/login", async (req, res) => 

  
    const  username, password  = req.body;

    const user = await User.findOne( username ).lean();

    userN = username;


    if (!user) 
        return res.json( status: 'error', error: 'Invalid username/password' )
    

    if (await bcrypt.compare(password, user.password)) 

        const token = jwt.sign( id: user._id, username: user.username , JWT_SECRET);

        res.redirect('/workspace');

        res.json( status: 'ok', data: token );

    

    res.json( status: 'ok', error: 'Invalid user/password' );


);

app.post('/signup', async (req, res) => 

   
    const  username, password: plainTextPassword  = req.body;

    userN = username;


    if (!username || typeof username !== 'string') 
        return res.json( status: 'error', error: 'Invalid username' );
    

    if (!plainTextPassword || typeof plainTextPassword !== 'string') 
        return res.json( status: 'error', error: 'Invalid password' );
    

    if (plainTextPassword.length < 5) 
        return res.json( status: 'error', error: 'Password too small. Should be atleast 6 characters long.' );
    

    const password = await bcrypt.hash(plainTextPassword, 10);

    try 
        const response = await User.create(
            _id: userN,
            username,
            password
        );
        console.log('user created succecfully: ', response);
        res.redirect('/workspace');
     catch (error) 
        if (error.code == 11000) 
            return res.json( status: 'error', error: 'Username already taken' );
        
        throw error
    

    res.json( status: 'ok' );

    const item1 = new Item(
        _id: userN,
        date: "Date",
        loc: "Location",
        title: "Title",
        passage: "Passage",
        file: "File"
    );

    defaultItems.push(item1);

);

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

    res.render("home");

);

app.get("/change-password", function (req, res) 

    res.render("changepass");

);

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( _id: userN , 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("/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(
        _id: userN,
        date: date,
        loc: location,
        title: title,
        passage: passage,
        file: file
    );

    item.save();

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

代码看起来可以正常工作，但实际上并没有。每次我尝试向用户添加另一个项目时，它都会给我错误。

【问题讨论】：

E11000 duplicate key error 表示将违反索引的唯一性约束。 _id 索引始终是唯一的，因此如果您尝试插入第二个具有相同 _id 值的文档，您将收到该错误。

好的，谢谢，我将使用不同的名称，而不是使用 _id。感谢您提供的信息，我会记住这一点。这回答了我的问题。

【参考方案1】：

来自MongoDB BSON guide“字段名称_id 保留用作主键；它的值在集合中必须是唯一的，是不可变的，并且可以是数组以外的任何类型。”

因此，您似乎正在尝试添加 2 个具有相同 _id 值的文档。 该字段被自动索引为唯一，所以如果您可以确定用户名是并且需要是唯一的，您可以继续使用它，但如果可以有多个相同的用户名，您应该保存它到一个单独的字段，并留下 _id 是。