🧠 Mastering MongoDB Queries: Insert, Find, Update, Delete and More
MongoDB is a powerful NoSQL database that uses a flexible, document-based model. In this guide, you’ll learn how to use key MongoDB queries including: Insert, Find, Update, and Delete. This is perfect for beginners and those switching from SQL to NoSQL.
📋 Table of Contents
- 1. Insert Documents
- 2. Find Documents
- 3. Update Documents
- 4. Delete Documents
- 5. Query Operators
- 6. Sort, Limit & Skip
- 7. Field Projection
- 8. Conclusion
📥 1. Insert Documents
Use insertOne() or insertMany() to add documents to a collection.
🔸 insertOne()
db.students.insertOne({
name: "Ravi",
age: 21,
course: "Computer Science"
});
🔸 insertMany()
db.students.insertMany([
{ name: "Anita", age: 22, course: "Electronics" },
{ name: "Rahul", age: 20, course: "Mathematics" }
]);
🔍 2. Find Documents
The find() method retrieves documents based on criteria.
🔸 Find All
db.students.find();
🔸 Find by Condition
db.students.find({ age: 21 });
🔸 Pretty Output
db.students.find().pretty();
🛠️ 3. Update Documents
You can modify documents using updateOne(), updateMany(), or replaceOne().
🔸 updateOne()
db.students.updateOne(
{ name: "Ravi" },
{ $set: { course: "Data Science" } }
);
🔸 updateMany()
db.students.updateMany(
{ age: { $gt: 20 } },
{ $set: { status: "Senior" } }
);
🔸 replaceOne()
db.students.replaceOne(
{ name: "Anita" },
{ name: "Anita", age: 23, course: "AI" }
);
🗑️ 4. Delete Documents
🔸 deleteOne()
db.students.deleteOne({ name: "Rahul" });
🔸 deleteMany()
db.students.deleteMany({ age: { $lt: 21 } });
⚙️ 5. Common Query Operators
$gt– Greater Than$lt– Less Than$in– In array$and,$or– Logical Operators
db.students.find({
$or: [
{ course: "Computer Science" },
{ age: { $lt: 22 } }
]
});
🧮 6. Sort, Limit & Skip
🔸 sort()
db.students.find().sort({ age: 1 }); // 1 = Asc, -1 = Desc
🔸 limit()
db.students.find().limit(3);
🔸 skip()
db.students.find().skip(2);
🎯 7. Field Projection
To return only selected fields:
db.students.find({}, { name: 1, course: 1, _id: 0 });
✅ 8. Conclusion
MongoDB provides a clean and powerful way to manage data using its intuitive query syntax. Whether you are inserting, reading, updating, or deleting data – MongoDB helps you work with documents efficiently.
Practice these queries using MongoDB Atlas or locally on your system. The more you experiment, the more confident you'll become!
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