MongoDB Update Document

Last Updated: 14 August, 2023

In MongoDB, we can update or modify one or more existing documents in a collection using the following methods:

We can specify the condition for update operations, which means we update specific documents in a collection based on the requirement. These conditions work the same as read operations in MongoDB.

In MongoDB, All write operations are atomic at the level of a single document.

To update a document, MongoDB provides update operators such as $set to modify field values.

For example, suppose we have a collection named student which has the following documents as given below:

 [
  {sid: 1, name: 'Ramesh', class: 'Nursery', roll: 15, gender: 'M'},
  {sid: 2, name: 'Gyatri', class: 'LKG', roll: 18, gender: 'F'},
  {sid: 3, name: 'John', class: 'Nursery', roll: 26, gender: 'M'},
  {sid: 4, name: 'Priya', class: 'UKG', roll: 10, gender: 'F'},
  {sid: 5, name: 'Suraj', class: 'LKG', roll: 12, gender: 'M'}
 ]

db.collection.updateOne()

The updateOne() method is used to update a single document in a collection. See the examples below.

Example 1: Update single document into a collection

 db.student.updateOne({sid: 2}, {$set: {roll: 55}});

Here, updating single document, if sid is 2 then update the roll field with new value.

Output

 /* 1 /
 {
    "acknowledged" : true,
    "matchedCount" : 1,
    "modifiedCount" : 1
 }

Example 2: Update two fields in a single document

 db.student.updateOne({sid: 2}, {$set: {roll: 55, class: 'STD-1'}});

Here, updating two fields in a single document, if sid is 2 then update the roll and class fields with new values.

Output

 /* 1 /
 {
    "acknowledged" : true,
    "matchedCount" : 1,
    "modifiedCount" : 1
 }

db.collection.updateMany()

MongoDB also allows us to update multiple documents in a collection using the updateMany() method. See the examples below.

Example 3: Update multiple documents in a collection

 db.student.updateMany({class: 'Nursery'}, {$set: {class: 'Play Group'}});

Here, we are updating multiple documents whose class field value is Nursery to new value Play Group.

Output

 / 1 */
 {
    "acknowledged" : true,
    "matchedCount" : 2,
    "modifiedCount" : 2
 }

Example 4: 'AND' operator with update documents

   db.student.updateMany(
         {class: "Nursery", gender: "M"}, 
         {$set: {class: "LKG"}})

Here, we are updating documents with AND condition that means only those documents will be updated whose class is 'Nursery' and gender is 'M'.

Output

 / 1 */
 {
    "acknowledged" : true,
    "matchedCount" : 2,
    "modifiedCount" : 2
 }

Example 5: 'OR' operator with update documents

 db.student.updateMany(
      {$or: [{class: 'LKG'}, {gender: 'F'}]},
      {$set: {class: "UKG"}})

Here, we are updating documents with OR condition that means those all documents will be updated whose class is 'LKG' or gender is 'F'.

Output

 / 1 */
 {
    "acknowledged" : true,
    "matchedCount" : 3,
    "modifiedCount" : 3
 }

db.collection.replaceOne()

The replaceOne() method replaces the first matching document in the collection that matches the filter, using the replacement document.

Example 6: Replace a document into a collection

   db.student.replaceOne(
         {class: 'Nursery'}, 
         {sid: 110, name: 'Dhiraj', roll: 25, gender: 'M'});

Here, this will replace first matching document of given criteria.

Output

 / 1 */
 {
    "acknowledged" : true,
    "matchedCount" : 1,
    "modifiedCount" : 1
 }

Reference: https://www.mongodb.com/docs/mongodb-shell/crud/update/