Mongoose - Save array of strings

I can't save an array of strings into my DB using Mongoose.

(Note all code below is simplified for ease of writing here)

So i declare a variable of a person schema I have:

var newPerson = new Person ({
    tags: req.body.tags
});

The schema itself looks like:

var personSchema = new mongoose.Schema({
  tags: Array
});

And when it comes to saving its just a simple:

newPerson.save(function(err) {
    //basic return of json
});

So using Postman I send in an array in the body - however everytime I check the DB, it just shows one entry with the array as a whole i.e. how I sent it:

Any ideas what extra I'm supposed to do?

Write up from my comment:

The way to specify an array of strings in mongoose is like so:

var personSchema = new mongoose.Schema({
tags: [{
    type: String
}]

However, the problem here is most-likely to do with Postman as it is sending the 'array' as a string. You can check this by checking the type of req.body.tags like so:

console.log(typeof req.body.tags)

If this returns a String, make sure to set the content-type in Postman to JSON as seen in this screenshot rather than the default 'form-data' option.

var schema = new Schema({
  name:    String,
  binary:  Buffer,
  living:  Boolean,
  updated: { type: Date, default: Date.now },
  age:     { type: Number, min: 18, max: 65 },
  mixed:   Schema.Types.Mixed,
  _someId: Schema.Types.ObjectId,
  decimal: Schema.Types.Decimal128,
  array: [],
  ofString: [String],
  ofNumber: [Number],
  ofDates: [Date],
  ofBuffer: [Buffer],
  ofBoolean: [Boolean],
  ofMixed: [Schema.Types.Mixed],
  ofObjectId: [Schema.Types.ObjectId],
  ofArrays: [[]],
  ofArrayOfNumbers: [[Number]],
  nested: {
    stuff: { type: String, lowercase: true, trim: true }
  },
  map: Map,
  mapOfString: {
    type: Map,
    of: String
  }
})

// example use

var Thing = mongoose.model('Thing', schema);

var m = new Thing;
m.name = 'Statue of Liberty';
m.age = 125;
m.updated = new Date;
m.binary = Buffer.alloc(0);
m.living = false;
m.mixed = { any: { thing: 'i want' } };
m.markModified('mixed');
m._someId = new mongoose.Types.ObjectId;
m.array.push(1);
m.ofString.push("strings!");
m.ofNumber.unshift(1,2,3,4);
m.ofDates.addToSet(new Date);
m.ofBuffer.pop();
m.ofMixed = [1, [], 'three', { four: 5 }];
m.nested.stuff = 'good';
m.map = new Map([['key', 'value']]);
m.save(callback);

Try changing the schema to

var personSchema = new mongoose.Schema({
  tags: [{type: String}]
});

or you can use Mixed type

var personSchema = new mongoose.Schema({
  tags: mongoose.Schema.Types.Mixed
});

EDIT

i think the problem is with assignment. Use:

person.tags.push("string to push");

1. On Schema:
   ( Since you have mentioned in the problem that it is an array of strings )

var personSchema = new mongoose.Schema({
  tags:{
     type:[String],
     required: true
  }
}); 

2. On Postman:
   

{
  "tags": ["css", "javascript", "mongoose", "node"]
}

3. On MongoDB

{
  "tags":["css", "javascript", "mongoose", "node"]
}

Similarly, you can create other types of primitive arrays and document arrays in the mongoose schema as:

({
  toys: [ToySchema],
  buffers: [Buffer],
  strings: [String],
  numbers: [Number]
  // ... etc
});

1. On Schema

techs: Array

2. On Postman

"techs": ["express","rect","html","css","scss"]

3. On DB (MongoDB)

"techs" : [ "epxress", "rect", "html", "css", "scss" ]

this will also work

var personSchema = new mongoose.Schema({
    tags: {
        type: [String], default: []
    }
});

var personSchema = new mongoose.Schema({
  tags: [{type: String}]
});

Use this in the schema.

Saving the Array:

var etc = new modename({yourprimaryid: primaryid});
						for (var i = 0; i < tag.length; i++) {
							etc.tag.push(tag[i]);
						}
						etc.save(function(err) {
                          //whatever you want here
						}

Firstly, as many people have noted, the schema needs to change to indicate that the tags field is intended to hold an array of strings, and not just a single one. So that needs to change to:

var personSchema = new mongoose.Schema({
  tags: [String]
});

The other thing you need to keep in mind (and which caused me a lot of trouble), is that when saving, make sure to use a fresh array for the tags field. For example, this won't work:

person.tags[0] = "new tag";
person.save();

Instead, you need to do something like:

person.tags = person.tags.slice(); // Clone the tags array
person.tags[0] = "new tag";
person.save();

Hope this helps.

Define a Schema:

const schema = new Schema({
  name: { type: String, required: true },
  tags: [String]
});

In postman add each element separately using the array syntax below

name:Thing
tags[]:task
tags[]:other
tags[]:thing

Return Data:

{
    "__v": 0,
    "name": "Thing",
    "_id": "5a96e8d0c7b7d1323c677b33",
    "tags": [
        "task",
        "other",
        "thing"
    ]
}

I had a simialr problem, In the model, do this :

tags : {[String], default: undefined}

So that it defaults to undefined unstead of an empty array, and instead of this:

const person = new Person({
    tags : req.body.tags
});

Do this :

const person = new Person();
person.tags = req.body.tags;