> For the complete MongoDB documentation index, see www.mongodb.com/docs/llms.txt

# Run Commands

To run commands in `mongosh`, you must first [connect to a MongoDB deployment.](https://www.mongodb.com/docs/mongodb-shell/connect.md#std-label-mdb-shell-connect)

## Format Input and Output

`mongosh` uses the [Node.js BSON parser](https://www.npmjs.com/package/bson) parser to parse [BSON](https://www.mongodb.com/basics/bson) data. You can use the parser's [EJSON](https://www.npmjs.com/package/bson#EJSON) interface to transform your data when you work with `mongosh`.

For examples that use EJSON, see: [EJSON.](https://www.mongodb.com/docs/mongodb-shell/reference/ejson.md#std-label-mongosh-ejson)

## Switch Databases

To display the database you are using, type `db`:

```sh
db
```

The operation should return `test`, which is the default database.

To switch databases, issue the `use <db>` helper, as in the following example:

```javascript
use <database>
```

To access a different database from the current database without switching your current database context, see the [`db.getSiblingDB()`](https://www.mongodb.com/docs/manual/reference/method/db.getSiblingDB.md#mongodb-method-db.getSiblingDB) method.

To list the databases available to the user, use the helper `show
dbs`.

### Create a New Database and Collection

To create a new database, issue the `use <db>` command with the database that you would like to create. For example, the following commands create both the database `myNewDatabase` and the [collection](https://www.mongodb.com/docs/manual/reference/glossary.md#std-term-collection) `myCollection` using the [`insertOne()`](https://www.mongodb.com/docs/manual/reference/method/db.collection.insertOne.md#mongodb-method-db.collection.insertOne) operation:

```javascript
use myNewDatabase
db.myCollection.insertOne( { x: 1 } );
```

If a collection does not exist, MongoDB creates the collection when you first store data for that collection.

## Terminate a Running Command

To terminate a running command or query in [`mongosh`](https://www.mongodb.com/docs/mongodb-shell/index.md#mongodb-binary-bin.mongosh), press `Ctrl + C`.

When you enter `Ctrl + C`, [`mongosh`:](https://www.mongodb.com/docs/mongodb-shell/index.md#mongodb-binary-bin.mongosh)

- interrupts the active command,

- tries to terminate the ongoing, server-side operation, and

- returns a command prompt.

If [`mongosh`](https://www.mongodb.com/docs/mongodb-shell/index.md#mongodb-binary-bin.mongosh) cannot cleanly terminate the running process, it issues a warning.

**Note:**

Pressing `Ctrl + C` in [`mongosh`](https://www.mongodb.com/docs/mongodb-shell/index.md#mongodb-binary-bin.mongosh) does not terminate asynchronous code. Asynchronous operations such as `setTimeout` or operations like `fs.readFile` continue to run.

There is no way to terminate asynchronous code in [`mongosh`](https://www.mongodb.com/docs/mongodb-shell/index.md#mongodb-binary-bin.mongosh). This is the same behavior as in the Node.js [REPL.](https://nodejs.org/api/repl.html)

Pressing `Ctrl + C` once will not exit [`mongosh`](https://www.mongodb.com/docs/mongodb-shell/index.md#mongodb-binary-bin.mongosh), press `Ctrl + C` twice to  exit [`mongosh`.](https://www.mongodb.com/docs/mongodb-shell/index.md#mongodb-binary-bin.mongosh)

You can also terminate a script from within the script code by calling the `exit(<code>)` command. For more information, refer to [Terminate a Script on Error.](https://www.mongodb.com/docs/mongodb-shell/write-scripts.md#std-label-mongosh-terminate-script)

## Command Exceptions

For commands whose output includes `{ ok: 0 }`, `mongosh` returns a consistent exception and omits the server raw output. The legacy `mongo` shell returns output that varies for each command.

## Clear the `mongosh` Console

The `cls` command clears the console. You can also clear the console with `Ctrl + L` and `console.clear()`.