MongoDB - Create Collection

MongoDB - Create Collection

createCollection() method

MongoDB db.createCollection(name, parameters) is used to create a collection.


The basic syntax of the createCollection() command is as follows:

db.createCollection(name, options)

In the name command , this is the name of the collection to be created. Options is a document that is used to specify the collection's configuration.

parameter A type Description
title line The name of the collection to be created
Options Document (Optional) Specify options for memory and indexing

The options parameter is optional, so only the name of the collection needs to be specified. Following is the list of options that you can use −

field A type Description
limited logical (Optional) If set to true, includes the limited collection. A limited collection is a fixed-size collection that automatically overwrites its oldest entries when it reaches its maximum size. If you specify true, you also need to specify a size parameter.
autoIndexId logical (Optional) If set to true, automatically create an index on the _id field. The default value is false.
the size number (Optional) Specifies the maximum size in bytes for a limited collection. If capped is true, then you also need to specify this field.
Maximum number (Optional) Specifies the maximum number of documents allowed in a limited collection.

When inserting a document, MongoDB first checks the size field of the constrained collection and then checks the max field.


The basic syntax of the createCollection() method without options is as follows:

> use test
switched to db test
> db . createCollection ( "mycollection" ) { "ok" : 1 } >

You can check the created collection with the show collection command .

> show collections
system . indexes

The following example shows the syntax of the createCollection() method with several important parameters:

> db . createCollection ( "mycol" , { capped : true , autoIndexId : true , size : 6142800 , max : 10000 } ) { "ok" : 1 } >    

In MongoDB, you don't need to create a collection. MongoDB creates a collection automatically when you insert any document.