This project is an experimental shell that implements most of the end-user functionality of the current mongo shell but expands it to include enhanced abilities.
The shell features the following advanced behaviors
- Advanced help system
- Plugins
- Multiple display output formats (legacy shell, extended json)
- ExtJSON
Integrated help system allowing per function help.
mongodb [test]> db.createView(Tab completion on the db.createView function returns full help.
Method: createView()
Creates a view </core/views> as the result of the applying the specified aggregation pipeline <aggregation-pipeline> to the source collection or view. Views act as read-only collections, and are computed on demand during read operations. MongoDB executes read operations on views as part of the underlying aggregation pipeline.
Parameters:
view string The name of the view to create.
source string The name of the source collection or view from which to create the view. The
name is not the full namespace of the collection or view; i.e. does not include
the database name and implies the same database as the view to create.
pipeline array An array that consists of the :ref:`aggregation pipeline stage
<aggregation-pipeline>`. {{op}} creates the view by applying the specified
``pipeline`` to the {{source}}. .. include::
/includes/extracts/views-public-definition.rst
[options] object Additional options for the method.
Return:
Promise
Examples:
// Create a View from a Single Collection
db.createView(
"managementFeedback",
"survey",
[ { $project: { "management": "$feedback.management", department: 1 } } ]
)
// Query a View
db.managementFeedback.find()
// Perform Aggregation Pipeline on a View
db.managementFeedback.aggregate([ { $sortByCount: "$department" } ] )
// Create a View from Multiple Collections
db.createView(
"orderDetails",
"orders",
[
{ $lookup: { from: "inventory", localField: "item", foreignField: "sku", as: "inventory_docs" } },
{ $project: { "inventory_docs._id": 0, "inventory_docs.sku": 0 } }
]
)
// Perform Aggregation Pipeline on a View
db.orderDetails.aggregate( [ { $sortByCount: "$item" } ] )
// Create a View with Default Collation
db.createView(
"placesView",
"places",
[ { $project: { category: 1 } } ],
{ collation: { locale: "fr", strength: 1 } }
)
This help can also be accessed by typing the following
mongodb [test]> db.createView.help()One of the revolutionary new features is the ability to leverage first-party, third-party or write your own plugins for the new shell. Infitive expandibility is possible.
To list the available plugin commands simply type plugin once in the shell and it will print the available plugin actions.
mongodb [test]> help pluginYou should see the following
------------------------
-- MongoDB Shell Help --
------------------------
help plugin Plugin level help
help plugin install Plugin install level help
help plugin list Plugin list level help
help plugin search [term] Plugin search level help
help plugin remove Plugin remove level help
The plugin search action lets you search for available plugins in the plugins repository. To see all available plugins simple write.
mongodb [test]> plugin searchIf you wish to narrow the search by a keyword simple do
mongodb [test]> plugin search topThis will return all plugins that contain the word top in their package name or description.
The install command lets you install a plugin using the shell. To install the sample top plugin just type the following and push enter.
mongodb [test]> plugin install topAfter a little while the plugin should be successfully installed. If you now type help you will see the new top namespace in the list of help topics.
mongodb [test]> helpreturns
------------------------
-- MongoDB Shell Help --
------------------------
Help supports:
help Full help.
help db Database level help
help collection Collection level help
help plugin Plugin management help
help top Monitor basic usage statistics for each collectionTo execut the plugin simply write
mongodb [test]> topThe plugin list action returns the currently installed plugins. Simply enter the command.
mongodb [test]> plugin listand you should see something like the following if the top plugin is installed.
mongo-shell-top 1.0.0 Mongo Top Shell Plugin
The plugin remove action will uninstall a plugin. Simply enter the command.
mongodb [test]> plugin remove topand the top plugin will be removed.
The new shell lets you set the default output format of the shell. By default it runs the legacy output format from the existing mongo shell but it also supports other possible output formats. Out of the box it comes with support for the extended json format.
To list the available formats simply type output
mongodb [test]> ouput
this will list the available output formats
Output Description
shell Mongo Shell output format
extjson Extended JSON output format
to switch to extended json output format simply type.
mongodb [test]> output extjson
Any results returned from an operation will not be serialized to the Extended JSON format allowing for simple copy paste between the shell and other tools such as compass.
The shell also exposes an Extended JSON serialzier and deserializer that works exactly as the standard Javascript JSON. The two following methods are available.
ExtJSON.parse()
ExtJSON.stringify()