MongoDB insertMany() Method
As the name suggests, the insertMany() method allows us to specify a set of documents and insert them all at once in a given collection.
The following shows the syntax of the insertMany() method:
[ , , ... ],
{
writeConcern: ,
ordered:
}
)
The parameter are as follows:
- Document – specifies an array of documents to insert into a given collection.
- writeConcern – defines the write concern parameters which overrides the default write concern. A write concern is used to define the level of acknowledgement requested from MongoDB for write ops.
- Ordered –defines whether the MongoDB instance should execute an ordered or unordered insert.
The method should return an acknowledgment statement which includes a Boolean statement and the number of inserted documents.
Let us take a look at a practical example.
Define a Collection
Let us start by creating a simple collection where we can insert sample data. Login into MongoDB Shell and run the command:
db.createCollection("employees")
The command above should create a new collection called employees.
Insert Multiple Documents With _id Field
MongoDB is a very flexible database. It allows us to insert documents without specifying the _id field. By default, MongoDB will generate a unique identifier for every document inserted in the collection
The example below shows how to use the insertMany() method to insert multiple documents without the _id field.
{ name: "Ryan", department: "Game Development", salary: 120000 },
{ name: "David", department: "Backend Development", salary: 108000 },
{ name: "Rachael", department: "Full Stack Development", salary: 110000 },
{ name: "James", department: "DevOps Development", salary: 110000 },
{ name: "Peter", department: "Game Development", salary: 123000 },
])
If we execute the query above, we should get an output as shown:
"acknowledged" :true,
"insertedIds" : [
ObjectId("632bd2f28b16030eebd4fad6"),
ObjectId("632bd2f28b16030eebd4fad7"),
ObjectId("632bd2f28b16030eebd4fad8"),
ObjectId("632bd2f28b16030eebd4fad9"),
ObjectId("632bd2f28b16030eebd4fada")
]
}
The above shows an acknowledgment message and the automatically generated id values.
We can locate the inserted documents as:
The command above should return the inserted documents as shown:
"_id" : ObjectId("632bd2f28b16030eebd4fad6"),
"name" : "Ryan",
"department" : "Game Development",
"salary" : 120000.0
}
{
"_id" : ObjectId("632bd2f28b16030eebd4fad7"),
"name" : "David",
"department" : "Backend Development",
"salary" : 108000.0
}
{
"_id" : ObjectId("632bd2f28b16030eebd4fad8"),
"name" : "Rachael",
"department" : "Full Stack Development",
"salary" : 110000.0
}
{
"_id" : ObjectId("632bd2f28b16030eebd4fad9"),
"name" : "James",
"department" : "DevOps Development",
"salary" : 110000.0
}
Insert Multiple Documents With _id Field
If we do not wish MongoDB to generated an _id value, we can explicitly specify the values for the _id column as shown in the example below:
{ _id: 1, name: "Ryan", department: "Game Development", salary: 120000 },
{ _id: 2, name: "David", department: "Backend Development", salary: 108000 },
{ _id: 3, name: "Rachael", department: "Full Stack Development", salary: 110000 },
{ _id: 4, name: "James", department: "DevOps Development", salary: 110000 },
{ _id: 5, name: "Peter", department: "Game Development", salary: 123000 },
])
In the example above, we explicitly specify the values of the _id column for each document inserted in the collection.
The query above should return:
"acknowledged" :true,
"insertedIds" : [
1.0,
2.0,
3.0,
4.0,
5.0
]
}
Unordered Insert
We can also perform an unordered insert by setting the ordered parameter to false as shown below:
{ _id: 1, name: "Ryan", department: "Game Development", salary: 120000 },
{ _id: 2, name: "David", department: "Backend Development", salary: 108000 },
{ _id: 3, name: "Rachael", department: "Full Stack Development", salary: 110000 },
{ _id: 4, name: "James", department: "DevOps Development", salary: 110000 },
{ _id: 5, name: "Peter", department: "Game Development", salary: 123000 },
], {ordered: false})
This is useful when working with duplicate documents.
Conclusion
In this post, we covered the fundamentals of working with MongoDB insertMany() method to add multiple documents to a given collection in a single command.
