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- Bulk.find.update()
Bulk.find.update()¶
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Tip
Starting in version 3.2, MongoDB also provides the
db.collection.bulkWrite()
method for performing bulk
write operations.
Description¶
-
Bulk.find.
update
(<update>)¶ Adds a
multi
update operation to a bulk operations list. The method updates specific fields in existing documents.Use the
Bulk.find()
method to specify the condition that determines which documents to update. TheBulk.find.update()
method updates all matching documents. To specify a single document update, seeBulk.find.updateOne()
.Bulk.find.update()
accepts the following parameter:Parameter Type Description update document or pipeline The modifications to apply. Can be one of the following:
Update document Contains only update operator expressions. Aggregation pipeline
Starting in MongoDB 4.2Contains only the following aggregation stages:
$addFields
and its alias$set
$project
and its alias$unset
$replaceRoot
and its alias$replaceWith
.
For more information on the update modification parameter, see the
db.collection.updateMany
reference page.The sum of the associated
<query>
document from theBulk.find()
and the update document must be less than or equal to themaximum BSON document size
.- To specify an upsert: true for this operation,
use with
Bulk.find.upsert()
. WithBulk.find.upsert()
, if no documents match theBulk.find()
query condition, the update operation inserts only a single document. - To specify arrayFilters to update specific array
elements, use with
Bulk.find.arrayFilters()
. - To specify the index to use for the associated
Bulk.find()
, seeBulk.find.hint()
. - To replace a document wholesale, see
Bulk.find.replaceOne()
.
Example¶
The following example initializes a Bulk()
operations builder
for the items
collection, and adds various multi
update
operations to the list of operations.
Update with Aggregation Pipeline¶
Starting in version 4.2, update methods can accept an aggregation pipeline. For example, the following uses:
- the
$set
stage which can provide similar behavior to the$set
update operator expression, - the aggregation variable
NOW
, which resolves to the current datetime and can provide similar behavior to a$currentDate
update operator expression. To access aggregation variables, prefix the variable with double dollar signs$$
and enclose in quotes.