MongoDB CRUD Operations

What are CRUD Operations?

CRUD stands for Create, Read, Update, and Delete - the four basic operations that can be performed on any database. MongoDB provides powerful methods to perform these operations efficiently.

Create Operations

Inserting Documents

MongoDB provides several methods to insert documents into a collection:

// Insert a single document
db.users.insertOne({
    name: "John Doe",
    age: 30,
    email: "john@example.com"
})

// Insert multiple documents
db.users.insertMany([
    { name: "Jane Doe", age: 25, email: "jane@example.com" },
    { name: "Bob Smith", age: 35, email: "bob@example.com" }
])

Read Operations

Querying Documents

MongoDB provides flexible querying capabilities:

// Find all documents
db.users.find()

// Find with filters
db.users.find({ age: { $gt: 25 } })

// Find with multiple conditions
db.users.find({
    age: { $gt: 25 },
    email: { $regex: /@example.com$/ }
})

// Find one document
db.users.findOne({ name: "John Doe" })

Update Operations

Modifying Documents

MongoDB provides various update operators:

// Update a single document
db.users.updateOne(
    { name: "John Doe" },
    { $set: { age: 31 } }
)

// Update multiple documents
db.users.updateMany(
    { age: { $lt: 30 } },
    { $inc: { age: 1 } }
)

// Replace a document
db.users.replaceOne(
    { name: "John Doe" },
    { name: "John Doe", age: 31, email: "john.doe@example.com" }
)

Delete Operations

Removing Documents

MongoDB provides methods to delete documents:

// Delete a single document
db.users.deleteOne({ name: "John Doe" })

// Delete multiple documents
db.users.deleteMany({ age: { $lt: 30 } })

Next Steps

Now that you understand CRUD operations, you can explore: