Population for references in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Mongoose library.

Express

const mongoose = require('[1]');

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Acors

Bmongoose

Cbody-parser

Dexpress

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'express' instead of 'mongoose'.

Forgetting to import Mongoose before using it.

The Mongoose library is imported using require('mongoose') to work with MongoDB in Express.

2fill in blank

medium

Complete the code to define a Mongoose schema for a User with a name field.

Express

const userSchema = new mongoose.Schema({ name: { type: [1], required: true } });

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AString

BNumber

CBoolean

DDate

Attempts:

3 left

💡 Hint

Common Mistakes

Using Number or Boolean for text fields.

Forgetting to set the type property.

The name field should be a string, so we use String as the type.

3fill in blank

hard

Fix the error in the code to populate the 'author' reference in a Post model query.

Express

Post.find().populate('[1]').exec((err, posts) => { console.log(posts); });

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Acomments

Btags

Cauthor

Dlikes

Attempts:

3 left

💡 Hint

Common Mistakes

Populating a field that is not a reference.

Using the wrong field name in populate.

To populate the referenced author data, use populate('author') matching the field name in the schema.

4fill in blank

hard

Fill both blanks to create a Mongoose model and export it.

Express

const [1] = mongoose.model('User', [2]);
module.exports = [1];

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AUser

BuserSchema

CpostSchema

DPost

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing model and schema names.

Forgetting to export the model.

The model is named 'User' and uses the userSchema. Then it is exported with the same name.

5fill in blank

hard

Fill all three blanks to query posts and populate both 'author' and 'comments' references.

Express

Post.find().populate('[1]').populate('[2]').exec((err, [3]) => {
  if (err) return console.error(err);
  console.log([3]);
});

Drag options to blanks, or click blank then click option'

Aauthor

Bcomments

Cposts

Dusers

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong field names in populate.

Mismatching the callback variable name.

We populate both 'author' and 'comments' fields, then receive the results in the 'posts' variable.