Updating a Single Document in MongoDB: The updateOne() Method

Learn how to effectively modify a single document in MongoDB collections using the updateOne() method. This guide will cover the various update operators and techniques, allowing you to precisely target and modify the desired document. Understand the behavior of updateOne() when multiple documents match the filter criteria.

MongoDB: Update Single Document using updateOne()

The updateOne() method in MongoDB updates a single document that matches the specified filter criteria. It modifies the first matching document even if multiple documents match.

Syntax

The syntax for the updateOne() method is:

db.collection.updateOne(filter, update, options)
        

Parameters:

• filter: The selection criteria for the update, similar to the find() method.
• update: A document or pipeline that contains modifications to apply.
• options: Optional. May include options for update behavior like upsert, writeConcern, collation, etc.

Sample Data

Insert the following documents into the employees collection:

db.employees.insertMany([
    { _id: 1, firstName: "John", lastName: "King", email: "john.king@abc.com", salary: 5000 },
    { _id: 2, firstName: "Sachin", lastName: "T", email: "sachin.t@abc.com", salary: 8000 },
    { _id: 3, firstName: "James", lastName: "Bond", email: "jamesb@abc.com", salary: 7500 },
    { _id: 4, firstName: "Steve", lastName: "J", email: "steve.j@abc.com", salary: 7000 },
    { _id: 5, firstName: "Kapil", lastName: "D", email: "kapil.d@abc.com", salary: 4500 },
    { _id: 6, firstName: "Amitabh", lastName: "B", email: "amitabh.b@abc.com", salary: 7000 }
])
        

Examples

1. **Update a Single Field**

Update the firstName field of the document with _id: 1:

db.employees.updateOne({_id: 1}, { $set: { firstName: 'Morgan' } })
        

Output:

{
  acknowledged: true,
  insertedId: null,
  matchedCount: 1,
  modifiedCount: 1,
  upsertedCount: 0
}
    

Check the updated document:

db.employees.find({_id: 1})
        

Output:

{
  _id: 1,
  firstName: 'Morgan',
  lastName: 'King',
  email: 'john.king@abc.com',
  salary: 5000
}
    

2. **Add a New Field**

Add the location field to the document with firstName: "Steve":

db.employees.updateOne({firstName: "Steve"}, { $set: { location: "USA" } })
        

Output:

{
  acknowledged: true,
  insertedId: null,
  matchedCount: 1,
  modifiedCount: 1,
  upsertedCount: 0
}
    

Check the updated document:

db.employees.find({firstName: "Steve"})
        

Output:

{
  _id: 4,
  firstName: "Steve",
  lastName: "J",
  email: "steve.j@abc.com",
  salary: 7000,
  location: "USA"
}
    

3. **Use the $inc Operator**

Increase the salary field by 500 for the document with firstName: "Steve":

db.employees.updateOne({firstName: "Steve"}, { $inc: { salary: 500 } })
        

Output:

{
  acknowledged: true,
  insertedId: null,
  matchedCount: 1,
  modifiedCount: 1,
  upsertedCount: 0
}
    

Check the updated document:

db.employees.find({firstName: "Steve"})
        

Output:

{
  _id: 4,
  firstName: "Steve",
  lastName: "J",
  email: "steve.j@abc.com",
  salary: 7500,
  location: "USA"
}
    

4. **Update Multiple Fields**

Update the email and lastName fields for the document with _id: 2:

db.employees.updateOne({_id: 2}, { $set: { lastName: "Tendulkar", email: "sachin.tendulkar@abc.com" } })
        

Output:

{
  acknowledged: true,
  insertedId: null,
  matchedCount: 1,
  modifiedCount: 1,
  upsertedCount: 0
}
    

Check the updated document:

db.employees.find({_id: 2})
        

Output:

{
  _id: 2,
  firstName: "Sachin",
  lastName: "Tendulkar",
  email: "sachin.tendulkar@abc.com",
  salary: 8000
}
    

5. **Upsert - Add if Not Exist**

Add a new document if no document matches the filter:

db.employees.updateOne({firstName: "Heer"}, { $set: { lastName: "Patel", salary: 2000 } }, { upsert: true })
        

Output:

{
  acknowledged: true,
  insertedId: ObjectId("6172a2e9ce7d5ca09d6ab082"),
  matchedCount: 0,
  modifiedCount: 0,
  upsertedCount: 1
}
    

Update Operators

Here are some common update operators you can use with updateOne():

For more details, refer to the MongoDB Update Operators documentation.