In MongoDB, db.createCollection(name, options) is used to create collection. But usually you don?t need to create collection. MongoDB creates collection automatically when you insert some documents. It will be explained later. First see how to create collection:
Syntax:
db.createCollection(name, options)
Here,
Name: is a string type, specifies the name of the collection to be created.
Options: is a document type, specifies the memory size and indexing of the collection. It is an optional parameter.
Following is the list of options that can be used.
| Field | Type | Description |
|---|---|---|
| Capped | Boolean | (Optional) If it is set to true, enables a capped collection. Capped collection is a fixed size collecction that automatically overwrites its oldest entries when it reaches its maximum size. If you specify true, you need to specify size parameter also. |
| AutoIndexID | Boolean | (Optional) If it is set to true, automatically create index on ID field. Its default value is false. |
| Size | Number | (Optional) It specifies a maximum size in bytes for a capped collection. Ifcapped is true, then you need to specify this field also. |
| Max | Number | (Optional) It specifies the maximum number of documents allowed in the capped collection. |
Let's take an example to create collection. In this example, we are going to create a collection name SSSIT.
>use test
>db.createCollection("SSSIT")To check the created collection, use the command "show collections".
>show collections
MongoDB creates collections automatically when you insert some documents. For example: Insert a document named seomount into a collection named SSSIT. The operation will create the collection if the collection does not currently exist.
>db.SSSIT.insert({"name" : "seomount"})
>show collections
SSSITIf you want to see the inserted document, use the find() command.
Syntax:
