MongoDB Update Documents

MongoDB Update Documents

In MongoDB, updating documents in a collection is done using the updateOne, updateMany, and replaceOne methods. These methods allow you to modify one or more documents within a collection based on specified criteria.

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Syntax

db.collection.updateOne(filter, update, options)
db.collection.updateMany(filter, update, options)
db.collection.replaceOne(filter, replacement, options)

The updateOne method updates a single document that matches the filter, updateMany updates multiple documents, and replaceOne replaces an entire document.

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Example MongoDB Update Documents

Let's look at some examples of how to update documents in the programGuru collection in MongoDB:

1. Update a Single Document

db.programGuru.updateOne(
    { name: "John Doe" },
    { $set: { age: 31 } }
)

This command updates the age field to 31 for the document where the name is John Doe.

2. Update Multiple Documents

db.programGuru.updateMany(
    { age: { $gt: 25 } },
    { $set: { status: "Active" } }
)

This command updates the status field to Active for all documents where the age is greater than 25.

3. Replace a Document

db.programGuru.replaceOne(
    { name: "Jane Smith" },
    { name: "Jane Smith", age: 26, email: "jane.smith@example.com", status: "Active" }
)

This command replaces the entire document where the name is Jane Smith with the new document.

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Full Example

Let's go through a complete example that includes switching to a database, creating a collection, inserting documents, updating them, and verifying the updates.

Step 1: Switch to a Database

This step involves switching to a database named myDatabase.

use myDatabase

In this example, we switch to the myDatabase database.

Step 2: Create a Collection

This step involves creating a new collection named programGuru in the myDatabase database.

db.createCollection("programGuru")

Here, we create a collection named programGuru.

Step 3: Insert Documents into the Collection

This step involves inserting documents into the programGuru collection.

db.programGuru.insertMany([
    { name: "John Doe", age: 30, email: "john.doe@example.com" },
    { name: "Jane Smith", age: 25, email: "jane.smith@example.com" },
    { name: "Jim Brown", age: 35, email: "jim.brown@example.com" }
])

We insert multiple documents into the programGuru collection.

Step 4: Update Documents in the Collection

This step involves updating documents in the programGuru collection.

Update a Single Document

db.programGuru.updateOne(
    { name: "John Doe" },
    { $set: { age: 31 } }
)

We update the age field to 31 for the document where the name is John Doe.

Verify the Update

db.programGuru.find({ name: "John Doe" }).pretty()

This command retrieves the document where the name is John Doe to verify the update.

Update Multiple Documents

db.programGuru.updateMany(
    { age: { $gt: 25 } },
    { $set: { status: "Active" } }
)

We update the status field to Active for all documents where the age is greater than 25.

Verify the Update

db.programGuru.find({ age: { $gt: 25 } }).pretty()

This command retrieves all documents where the age is greater than 25 to verify the update.

Replace a Document

db.programGuru.replaceOne(
    { name: "Jane Smith" },
    { name: "Jane Smith", age: 26, email: "jane.smith@example.com", status: "Active" }
)

We replace the entire document where the name is Jane Smith with the new document.

Verify the Replacement

db.programGuru.find({ name: "Jane Smith" }).pretty()

This command retrieves the document where the name is Jane Smith to verify the replacement.

Conclusion

The MongoDB update documents operation is crucial for modifying data within collections. Understanding how to update single and multiple documents, as well as replace entire documents, is essential for effective data management in MongoDB.