Search and filter data in Mongo DB using mongoose

Question

var questionSchema = new Schema({
    category: { name:
        {
        type: String,
        lowercase: true,
        required: [true, 'Category is a required field']
    },
        question:[
            {
                q: {
                    type: String,
                    lowercase: true
                    
                },
                options: {
                    option1:{
                        type: String,
                        lowercase: true
                        
                    },
                    option2:{
                        type: String,
                        lowercase: true
                       ]
                    },
                    option3:{
                        type: String,
                        lowercase: true
                        
                    },
                    option4:{
                        type: String,
                        lowercase: true
                        
                    },
                },
                ans: {
                    type: String,
                    lowercase: true
                  
                },
                level:{
                    type: String,
                    lowercase: true
               
                }

            }

        ]
    },


},
    {
        strict: true,
        runSettersOnQuery: true,
        timestamps: {
            createdAt: 'created', updatedAt: 'updated'
        }
    });

This is my question schema. I am trying to get all the questions of a particular category. Till now I have tried this ---

function (req,res,next) {
    console.log(req.params.qcategory);
    Question.find({
        category:{
            name: req.params.qcategory,
        }
    },'', function (err,data) {
        if (err) {
            err.status = 406;
            return next(err);
        }
        console.log(data);
        return res.status(201).json({
            message: ' success.',data:data
        })
    })
};

In req.params.qcategory it contains the name of the category like 'programming' for instance. But it returned me an empty array. **PS. There are questions of programming category in my DB. Then What am i doing wrong ???

Also is there a way to first check what category a question is and then add to the question array inside that particular category. I don't want to add questions with categories again and again instead i want to check if that category already exists in the database and push the question inside the array of that question category. For instance if a question is of 'programming' category and in the database there is already a question which is of again a 'programming' category then push the question inside the array of programming category.

If my questions are not clear then please comment I will respond quickly.

Answer 1

Try this, Not tested

function (req,res,next) {
console.log(req.params.qcategory);
Question.find({
    "category.name": req.params.qcategory,}
 , function (err,data) {
    if (err) {
        err.status = 406;
        return next(err);
    }
    console.log(data);
    return res.status(201).json({
        message: ' success.',data:data
    })
})
};

Replace the {category:{name:req.params.qcategory}} with {"category.name":req.params.qcategory}.

read more on mongodb's Query Embedded Documents https://docs.mongodb.com/.../method/db.collection.find/