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- db.collection.insertMany()
db.collection.insertMany()¶
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Definition¶
-
db.collection.insertMany()¶ New in version 3.2.
Inserts multiple documents into a collection.
The
insertMany()method has the following syntax:Parameter Type Description documentdocument An array of documents to insert into the collection. writeConcerndocument Optional. A document expressing the write concern. Omit to use the default write concern. orderedboolean Optional. A boolean specifying whether the mongodinstance should perform an ordered or unordered insert. Defaults totrue.Returns: A document containing: - A boolean
acknowledgedastrueif the operation ran with write concern orfalseif write concern was disabled - An array of
_idfor each successfully inserted documents
- A boolean
Behaviors¶
Given an array of documents, insertMany()
inserts each document in the array into the collection.
Execution of Operations¶
By default documents are inserted in order.
If ordered is set to false, documents are inserted in an unordered
format and may be reordered by mongod to increase performance.
Applications should not depend on ordering of inserts if using an unordered
insertMany().
Each group of operations can have at most
1000 operations.
If a group exceeds this limit,
MongoDB will divide the group into
smaller groups of 1000 or less. For example, if the queue consists of 2000
operations, MongoDB creates 2 groups, each with 1000 operations.
The sizes and grouping mechanics are internal performance details and are subject to change in future versions.
Executing an ordered list of operations on a
sharded collection will generally be slower than executing an
unordered list
since with an ordered list, each operation must wait for the previous
operation to finish.
Collection Creation¶
If the collection does not exist, then insertMany()
creates the collection on successful write.
_id Field¶
If the document does not specify an _id field, then mongod
adds the _id field and assign a unique
ObjectId for the document. Most
drivers create an ObjectId and insert the _id field, but the
mongod will create and populate the _id if the driver or
application does not.
If the document contains an _id field, the _id value must be
unique within the collection to avoid duplicate key error.
Error Handling¶
Inserts throw a BulkWriteError exception.
Excluding Write Concern errors, ordered operations stop after an error, while unordered operations continue to process any remaining write operations in the queue.
Write concern errors are displayed in the writeConcernErrors field, while
all other errors are displayed in the writeErrors field. If an error is
encountered, the number of successful write operations are displayed instead
of a list of inserted _ids. Ordered operations display the single error
encountered while unordered operations display each error in an array.
Examples¶
The following examples insert documents into the products
collection.
Insert Several Document without Specifying an _id Field¶
The following example uses db.collection.insertMany() to insert
documents that do not contain the _id field:
The operation returns the following document:
Because the documents did not include _id,
mongod creates and adds the _id field for each document and
assigns it a unique ObjectId value.
The ObjectId values are specific to the machine and time when the
operation is run. As such, your values may differ from those in the
example.
Insert Several Document Specifying an _id Field¶
The following example/operation uses insertMany() to
insert documents that include the _id field. The value of _id must be
unique within the collection to avoid a duplicate key error.
The operation returns the following document:
Inserting a duplicate value for any key that is part of a unique
index, such as _id, throws an exception. The following attempts to insert
a document with a _id value that already exists:
Since _id: 13 already exists, the following exception is thrown:
Note that one document was inserted: The first document of _id: 13 will
insert successfully, but the second insert will fail. This will also stop
additional documents left in the queue from being inserted.
With ordered to false, the insert operation would continue with any
remaining documents.
Unordered Inserts¶
The following attempts to insert multiple documents with _id field and
ordered: false. The array of documents contains two documents with
duplicate _id fields.
The operation throws the following exception:
While the document with item: "medium box" and item: "tape"
failed to insert due to duplicate _id values,
nInserted shows that the remaining 5 documents were inserted.
Using Write Concern¶
Given a three member replica set, the following operation specifies a
w of majority and wtimeout of 100:
If the primary and at least one secondary acknowledge each write operation within 100 milliseconds, it returns:
If the total time required for all required nodes in the replica set to
acknowledge the write operation is greater than wtimeout,
the following writeConcernError is displayed when the wtimeout period
has passed.
This operation returns: