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Pavithra Sai
Pavithra Sai

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Hands-On CRUD Operations in MongoDB Using a Student Schema

MongoDB is a popular NoSQL database that stores data in flexible, JSON-like documents rather than traditional tables. In this tutorial, we’ll explore CRUD operations (Create, Read, Update, Delete) using a simple college student schema. By the end, you’ll be comfortable performing these operations in MongoDB Atlas.

Student Schema

Each student document follows this structure:

{
  "student_id": "S001",
  "name": "Santhosh",
  "age": 20,
  "department": "CSBS",
  "year": 2,
  "cgpa": 9
}
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We will use a collection called students to store these documents.

1️⃣ Create (Insert) Students

We’ll insert 5 student records into the students collection.

  { "student_id": "S001", "name": "Santhosh", "age": 20, "department": "CSBS", "year": 2, "cgpa": 9 },
  { "student_id": "S002", "name": "Kiran", "age": 21, "department": "CSE", "year": 3, "cgpa": 8.5 },
  { "student_id": "S003", "name": "Anita", "age": 19, "department": "ECE", "year": 2, "cgpa": 7.8 },
  { "student_id": "S004", "name": "Ramesh", "age": 22, "department": "CSE", "year": 3, "cgpa": 8.2 },
  { "student_id": "S005", "name": "Priya", "age": 20, "department": "CSBS", "year": 1, "cgpa": 9.1 }
]);
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💡 Tip: insertMany() allows inserting multiple documents in one
command.

2️⃣ Read (Query) Students

Display all students:

db.students.find().pretty();
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Find students with CGPA > 8:

db.students.find({ "cgpa": { $gt: 8 } });
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Find students in the Computer Science department (CSE):
db.students.find({ "department": "CSE" });
`

3️⃣ Update Students

Update CGPA of a specific student (S002):


db.students.updateOne(
{ "student_id": "S002" },
{ $set: { "cgpa": 9 } }
);

Increase year of all 3rd-year students by 1:

`
db.students.updateMany(
{ "year": 3 },
{ $inc: { "year": 1 } }
);

`

💡 Tip: $set updates a field, while $inc increments numerical values.

4️⃣ Delete Students

Delete a student by student_id (S003):


db.students.deleteOne({ "student_id": "S003" });

Delete all students with CGPA < 7.5:


db.students.deleteMany({ "cgpa": { $lt: 7.5 } });

Conclusion

In this tutorial, we explored how to create, read, update, and delete student records in MongoDB using a simple schema. MongoDB Atlas makes database management interactive and easy, giving us hands-on experience with real-world operations.

Final Collection Sample


[{ "student_id": "S002", "name": "Kiran", "age": 21, "department": "CSE", "year": 3, "cgpa": 8.5 },
{ "student_id": "S003", "name": "Anita", "age": 19, "department": "ECE", "year": 2, "cgpa": 7.8 },
{ "student_id": "S004", "name": "Ramesh", "age": 22, "department": "CSE", "year": 3, "cgpa": 8.2 }]

📌 Deliverables for this assignment:

  • MongoDB queries (insert, find, update, delete)
  • Screenshots of query execution in MongoDB Atlas
  • Export of the final students collection as JSON/CSV

Special thanks to @santhoshnc Sir for guiding and encouraging me throughout this assignment. Your mentorship made learning MongoDB hands-on and enjoyable! 🙏

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