The process of modifying MongoDB data involves using the update() or updateOne() method. The update() method is used to update multiple documents, and its syntax is: db.collection.update(query, update, options). The updateOne() method is used to update a single document, and its syntax is: db.collection.updateOne(query, update, options). In addition to this, MongoDB also provides many other update operators such as $inc, $push, $pull, and $rename.
How to modify data in MongoDB
The process of modifying data in MongoDB involves using update( )
method or updateOne()
method.
update() method
update()
method is used to update multiple documents in a collection. The syntax is:
<code>db.collection.update(query, update, options)</code>
Among them:
-
query
: Query conditions used to select documents to be updated. -
update
: An update is to be applied to the document of the matching document. -
options
: Optional options, such asupsert
(create the document if it does not exist) andmulti
(update all matching documents ).
updateOne() method
updateOne()
method is used to update a single document in the collection. The syntax is:
<code>db.collection.updateOne(query, update, options)</code>
Among them:
-
query
: Query conditions used to select documents to be updated. -
update
: An update is to be applied to the document of the matching document. -
options
: Optional options, such asupsert
(create the document if it does not exist).
Example
Use the update()
method to update multiple documents:
<code>db.users.update( { age: { $lt: 30 } }, { $set: { isYoung: true } }, { multi: true } );</code>
This will set the isYoung
field to true
for all users younger than 30 years old.
Update a single document using the updateOne()
method:
<code>db.users.updateOne( { name: "John" }, { $inc: { age: 1 } } );</code>
This will increase the age of the user named "John" by 1.
Other update operators
In addition to the $set
update operator, MongoDB also provides many other update operators, such as:
-
$inc
: Increase the value of a numeric field. -
$push
: Add elements to the array field. -
$pull
: Remove elements from an array field. -
$rename
: Rename the field.
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