# Mongoose

https://mongoosejs.com/ (opens new window)

simplifies writing

const mongoose = require('mongoose');
mongoose.connect('mongodb://localhost:27017/test', {useNewUrlParser: true, useUnifiedTopology: true});

const Cat = mongoose.model('Cat', { name: String });

const kitty = new Cat({ name: 'Zildjian' });
kitty.save().then(() => console.log('meow'));

# Connect to Database

const mongoose = require('mongoose');
mongoose.connect('mongodb://localhost:27017/yourDB', {useNewUrlParser: true, useUnifiedTopology: true});

# Create - Schema

Blueprint -> how should the data in the collection be structured?

You can only have Fields that are specified in the Schema

const fruitSchema = new mongoose.Schema ({
    name: {
    	type: String,
    	required: true
  	},
    rating: Number,
    review: String,
  	array: [String]
});

oder eventuell auch nur: ???

const intemsSchema = {
  name: String
}

# use the Schema to create a new Model:

const Fruit = mongoose.model("Fruit", fruitSchema);

The first Argument is alway a string in singular form -> mongoose will create plural for the collection (Fruit -> fruits will be the name of the collection)

-> can be disabled:

You can do this in 5.0.0-rc0:

mongoose.pluralize(null);
This will make mongoose not pluralize collection names at all, so mongoose.model('User', schema) will store documents in the 'User' collection.

# Create Document from the model:

const fruit = new Fruit ({
    name: "Apple",
    rating: 7,
    review: "Pretty solid as a fruit"
});
fruit.save();

# save to collection

fruit.save();

might be good to add a error-check-callback

 post.save((err) => {
      if (!err){
        res.redirect("/");
      }
    });

# insertMany()

https://mongoosejs.com/docs/api/model.html#model_Model.insertMany (opens new window)

const kiwi = new Fruit ({
    name: "Kiwi",
    rating: 10,
    review: "The best fruit"
})

const orange = new Fruit ({
    name: "Orange",
    rating: 4,
    review: "Too sour"
})

const banana = new Fruit ({
    name: "Banana",
    rating: 3,
    review: "Weird texture",
})

Fruit.insertMany([kiwi, orange, banana], function(err) {
    if (err) {
        console.log(err);
    } else {
        console.log("successfully saved the fruits to fruitsDB");
    }
} )

# Read - find()

>ModelName>.find({condition<}, (err, results) => {
	//Use the found results docs
})

Fruit.find((err, fruits) => {
    if (err) {
        console.log(err);
    } else {
        console.log(fruits);
    }
})

-> gives an array of JS-Objects. fruits

Fruit.find((err, result) => {
    if (err) {
        console.log(err);
    } else {
        mongoose.connection.close();
        result.forEach(element =>  {
            console.log(element.name);
        })
    }
})

# Close connection

good practice: Close the connection to the Database once you're done..

mongoose.connection.close();

# Model Methods

https://mongoosejs.com/docs/api/model.html (opens new window)

# Validation

https://mongoosejs.com/docs/validation.html (opens new window)

add validation to the Schema:

Built in-Validators, zB

required
min / max for Numbers
etc,

const fruitSchema = new mongoose.Schema ({
    name: {
    	type: String,
    	required: true
  	},
    rating: {
        type: Number,
        min: 1,
        max: 10
    }, 
    review: String
});

-> if rating is different than 1-10 -> document doesn`t get added

# Update

update
updateMany
updateOne

Fruit.updateOne({_id:"60255dfb7c758f4905a8e136"}, {name: "Peach"}, (err) => {
    if(err) {
        console.log(err);
    } else {
        mongoose.connection.close();
        console.log("👍Sucessfully updated");
    }
})

# Delete

Fruit.deleteOne({name: "Peach"}, (err) => {
    if(err) {
                console.log('❗️'+ err);
    } else {
        mongoose.connection.close();
        console.log("👍Sucessfully deleted");
    }
});

condition / callback

# deleteMany

<ModelName>.deleteMany{
	{conditions},
	function(err){
	
	}
};

leave out conditions to delete all

# Relationships

out schema of other Collection in the Schema:

const personSchema = new mongoose.Schema ({
    name: String,
    age: Number,
    favoriteFruit: fruitSchema
});


const person = new Person ({
   name: "Amy",
   age: 12,
   favoriteFruit: pineapple
})

$pull

MongoDB-operators

https://docs.mongodb.com/manual/reference/operator/update/pull/ (opens new window)

findOneAndUpdate()

List.findOneAndUpdate({}, {}, callback)

# Mongoose Links

← MongoDB with NodeJs