mongoose.md

Mongoose guide from MongoDB

https://www.mongodb.com/developer/languages/javascript/getting-started-with-mongodb-and-mongoose/

Setup

module type will allow us to use top-level await

"scripts": {
  "dev": "nodemon index.js"
},
"type": "module",

Two ways to create an User

With save()

await new User({name: "Foo}).save()

With create()

const user = await User.create({name: "Foo"})

This method is much better! Not only can we insert our document, but we also get returned the document along with its _id when we console log it.

const article = await Blog.create({
  title: 'Awesome Post!',
});

console.log(article);

Update User

const user = await User.create({name: "Foo"})

user.name = "Bar";

await user.save()

Finding data

const article = await Blog.findById("62472b6ce09e8b77266d6b1b").exec();
console.log(article);

Notice that we use the exec() Mongoose function. This is technically optional and returns a promise. In my experience, it’s better to use this function since it will prevent some head-scratching issues. If you want to read more about it, check out this note in the Mongoose docs about promises.

Projecting document fields

Just like with the standard MongoDB Node.js driver, we can project only the fields that we need. Let’s only get the title, slug, and content fields.

const article = await Blog.findById("62472b6ce09e8b77266d6b1b", "title slug content").exec();

console.log(article);

Automatic type inference

https://mongoosejs.com/docs/typescript/schemas.html#automatic-type-inference

There are a few caveats for using automatic type inference:

• You need to set strictNullChecks: true or strict: true in your tsconfig.json. Or, if you're setting flags at the command line, --strictNullChecks or --strict. There are known issues with automatic type inference with strict mode disabled.
• You need to define your schema in the new Schema() call. Don't assign your schema definition to a temporary variable. Doing something like const schemaDefinition = { name: String }; const schema = new Schema(schemaDefinition); will not work.
• Mongoose adds createdAt and updatedAt to your schema if you specify the timestamps option in your schema, except if you also specify methods, virtuals, or statics. There is a known issue with type inference with timestamps and methods/virtuals/statics options. If you use methods, virtuals, and statics, you're responsible for adding createdAt and updatedAt to your schema definition.

If automatic type inference doesn't work for you, you can always fall back to document interface definitions.