Myprojects/backend/s-34/discussion/index.js

// CRUD Operations

/*
	- CRUD Operations are the heart of any backend application.
	- Mastering the CRUD operations is essential for any developer
	- CRUD stands for CREATE, READ, UPDATE, and DELETE 
*/


// [SECTION] Inserting documents (Create)
	
	// Insert One Document
	/*
		Syntax:
			db.collectionName.insertOne({object});
	*/

	db.users.insertOne({
		firstName: "Jane",
		lastName: "Doe",
		age: 21,
		contact: {
			phone: "87654321",
			email: "janedoe@gmail.com"
		},
		course: ["CSS", "JavaScript", "Python"],
		department: "none"
	});

	// Insert Many
	/*
		Syntax:
			db.collectionName.insertMany([{Object A}, {Object B}]);
	*/

	db.users.insertMany([
		{
			firstName: "Stephen",
			lastName: "Hawking",
			age: 79,
			contact: {
				phone: "87654321",
				email: "stephenhawking@gmail.com"
			},
			course: ["Python", "React", "PHP"],
			department: "none"
		},
		{
			firstName: "Neil",
			lastName: "Armstrong",
			age: 82,
			contact: {
				phone: "87654321",
				email: "neilarmstrong@gmail.com"
			},
			course: ["React", "Laravel", "Sass"],
			department: "none"
		}

	]);

// [SECTION] Finding Documents (Read)

	// Find Single Document
		/*
			Syntax:
				db.collectionName.findOne();
				db.collectionName.findOne({ field: value });
		*/

	// Leaving the search criteria empty will retrieve ALL the documents
	db.users.find();

	// This will retrieve the first document
	db.users.findOne();
						// criteria
	db.users.findOne({ firstName: "Stephen" });

	// Finding Multiple Documents
	/*
		Syntax:
			db.collectionName.find({ fieldA: valueA });
	*/

	db.users.find({ department: "none" });

	// Finding multiple documents with multiple parameters (criteria)
	db.users.find({ department: "none", age: 82 });

// [SECTION] Updating Documents (Update)

	// Updating a single document

	// Creating document to update
	db.users.insertOne({
		firstName: "Test",
		lastName: "Test",
		age: 0,
		contact: {
			phone: "000000",
			email: "test@gmail.com"
		},
		courses: [],
		department: "none"
	});


	/*
		- Just like the "find" methos, methods that only manipulate a sigle document will only manipulate a single document will only update the FIST document that matches the search criteria
		- Syntax:
			db.collectionName.updateOne({criteria}, {$set: {field: value}});
	*/

	db.users.updateOne({ firstName: "Test" }, {
		$set: {
			firstName: "Bill",
			lastName: "Gates",
			age: 65,
			contact: {
				phone: "12345678",
				email: "bill@gmail.com"
			},
			courses: ["PHP", "Laravel", "HTML"],
			department: "Operations",
			status: "active"
		}
	});

	db.users.find({ firstName: "Bill" });

	// Another Example using _id
	db.users.updateOne({ _id: ObjectId("6514da527c5d7043df600f54") }, {
		$set: {
			firstName: "Elon",
			lastName: "Musk",
			age: 65,
			contact: {
				phone: "12345678",
				email: "elon@gmail.com"
			},
			courses: ["PHP", "Laravel", "HTML"],
			department: "Operations",
			status: "active"
		}
	});

	db.users.updateOne({ _id: ObjectId("6514da527c5d7043df600f54") }, {
		$set: {
			firstName: "Bill",
			lastName: "Gates"
		}
	});

	// Updating multiple documents
	/*
		Syntax:
			db.collectionName.updateMany({ criteria }, {$set: { field: value }});
	*/

	db.users.updateMany({department: "none"}, {
		$set: {
			department: "HR"
		}
	});

	db.users.find();


	// Replace One
	/*
		- Can be used if replacing the whole document is necessary.
		- Syntax:
			db.collectionName.replaceOne( { criteria }, { field: value } );
	*/ 

	db.users.replaceOne({firstName: "Bill"}, {
		
		firstName: "Bill",
		lastName: "Gates",
		age: 70,
		contact: {
			phone: "123123123",
			email: "billgates@gmail.com"
		},
		courses: ["PHP", "Laravel", "CSS"],
		department: "Operations"
		
	});

// [SECTION] Deleting Documents (Delete)

	// Create a document to delete
	db.users.insert({
		firstName: "test"
	});

	// Deleting a single Document
	/*
		Syntax:
			db.collectionName.deleteOne({criteria});
	*/
	db.users.deleteOne({
		firstName: "test"
	});

	db.users.find();

	// Delete Many
	/*	

		DO NOT USE: db.collectionName.deleteMany();

		Syntax:
			db.collectionName.deleteMany({criteria});
	*/

	db.users.deleteMany({
		firstName: "Bill"
	});

	db.users.find();

// TAKE HOME QUIZ

	// [SECTION] Advanced Queries

	// 1. Query an embedded document
	/*
		- find all the document with the following contact:
			phone: "87654321",
			email: "stephenhawking@gmail.com"
	*/

	// 2. Query on nested Field
	/*
		- find the document that has an email of "janedoe@gmail.com"
	*/

	// 3. Query an Array with Exact Elements
	/*
		- find a document with the has the courses
			- CSS
			- JavaScript
			- Python

	*/

	// 4. Querying an array without regard to order
	/*
		- find all the documents with the following courses
			- React
			- Python 
	*/