Question 115467 in Mongodb Question posted in
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Mongodb – Not getting any result when querying mongo database in nodejs

I am trying to query my database like this

const Admin = require("./model/Admin");

    module.exports = {
    
        validateUser : (uName, pwd) => {
            mongoose.connect("mongodb://127.0.0.1:27017/TeamDK")
            
            //console.log("Uname: " + uName + ", Pwd: " + pwd)
            
            res =  Admin.findOne({ initial: "tt" }).exec()
        }        
    }

In the case above, nothing is returned. The value of res is just null.

I also tried using a call back like this

res =  Admin.findOne({ initial: "tt" }, (err, val) => {
console.log(res)

Using a callback, the output of res is different. I have added a screenshot of this, and only part of it is shown, as it is very big.
enter image description here

I’m sure there is a document in my Model collection. When using monosh like this
TeamDK> db.Admin.findOne({ initial: "tt" }), this is what I get

{
  _id: ObjectId("63ebbd6c59097f4a25f23d31"),
  firstName: 'Test',
  initial: 'tt',
  lastName: 'Unknown',
  email: '[email protected]',
  password: '123',
  role: 4
}

If it’s of any use, my model looks like this:

const adminSchema = mongoose.Schema({
    firstName : { 
        type : String,    
        required : [true, "Why no name?"]
    },
    initial: {
        type: String,
        required: [true, "Why no initials?"],
        index: {unique: true }
    },
    lastName : {
        type : String,
        required : [true, "Why no last name?"]
    },
    email : {
        type : String,
        required : [true, "Then how are we gonna contact you?"],
        index: {unique: true }
    },
    password : {
        type : String,
        required : [true, "Come one man"]
    },
    dateCreate : { 
        type : Date, 
        default : Date.now 
    }, 
    role : {
        type : mongoose.Types.ObjectId,
        ref : "role"
    }     
})

module.exports = mongoose.model("Admin", adminSchema);

I’ve spent almost a day trying to fix this, tried following guids on https://mongoosejs.com/ and tried looking for similar problems here on stackoverflow, but I just can’t figure out what I’m doing wrong

————————- Update —————————

I have also tried making the function async, and use await. I tried isolating the code in a new file and doing like this

const mongoose = require ("mongoose");
const Admin = require("./model/Admin");

async function testAdmin() {
    await mongoose.connect("mongodb://127.0.0.1:27017/TeamDK")            
    
    res = await Admin.findOne({ initial: "tt" }).exec()

    console.log(res)
}

testAdmin()

I also tried removing the exec(), doing

res = await Admin.findOne({ initial: "tt" })

I’m still getting null returned. Any other suggestions are most welcome

————————- Update —————————

I have just noticed that if I do: res = await Admin.find() it works. Though it finds all the documents, and I only need a specific one, but it shows that it does contact the database. For some reason, it does not seem to accept the res = await Admin.findOne(...)

Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    I finally found out what the issue is. For some reason, it's as if the document that I was querying doesn't exist when I try to find it through node.js. I can find it when using mongosh though. I tried to query another document in the collection, and that one it found. So I tried yet another one, and that one it also finds. It seems to find all other, except this one (no matter which field I use as argument, it just returns null):

    {
  _id: ObjectId("63ebbd6c59097f4a25f23d31"),
  firstName: 'Test',
  initial: 'tt',
  lastName: 'Unknown',
  email: '[email protected]',
  password: '123',
  role: 4
}

    Yet I created it exactly the same way as all the others. I have no idea why I can't query this in nodejs, and it's a problem if it should ever act like that in an application. Thankfully this is just practice. It's very likely that they error is at my side, but I haven't located it.

    So should anyone experience the issue of not being able to access a document that you're certain is there (using nodejs), try see if you can access another document in the collection


  2. 0

    The .findOne is asynchronous, we must use await or callback to receive its result:

    const Admin = require("./model/Admin");

module.exports = {
    validateUser : async (uName, pwd) => {
        await mongoose.connect("mongodb://127.0.0.1:27017/TeamDK") // It's better to put this connect function somewhere else, not in the Model
            
        res = await Admin.findOne({ initial: "tt" });
        return res;
    }        
}

    Then use it a controller like this, example in Express

    // The connect function is better here
// mongoose.connect("mongodb://127.0.0.1:27017/TeamDK") 

app.post('/', async (req, res) => {
    const result = await validateUser('username', 'password');
    res.json(result);
})
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