mongo Shell Quick Reference快速参考¶

mongo Shell Command History命令历史记录¶

You can retrieve previous commands issued in the mongo shell with the up and down arrow keys.您可以使用上下箭头键检索mongo shell中以前发出的命令。Command history is stored in ~/.dbshell file.命令历史记录存储在~/.dbshell文件中。See .dbshell for more information.有关详细信息，请参阅.dbshell。

Command Line Options命令行选项¶

The mongo shell can be started with numerous options.mongo shell可以从许多选项开始。See mongo shell page for details on all available options.有关所有可用选项的详细信息，请参阅mongo shell页面。

The following table displays some common options for mongo:下表显示了mongo的一些常见选项：

Command Helpers¶

The mongo shell provides various help. The following table displays some common help methods and commands:

Basic Shell JavaScript Operations¶

The mongo shell provides a JavaScript API for database operations.

In the mongo shell, db is the variable that references the current database. The variable is automatically set to the default database test or is set when you use the use <db> to switch current database.

The following table displays some common JavaScript operations:

coll = db.myCollection;

coll.find();

For more information on performing operations in the shell, see:

• MongoDB CRUD Operations
• mongo Shell Methods

Keyboard Shortcuts¶

The mongo shell provides most keyboard shortcuts similar to those found in the bash shell or in Emacs. For some functions mongo provides multiple key bindings, to accommodate several familiar paradigms.

The following table enumerates the keystrokes supported by the mongo shell:

Queries¶

In the mongo shell, perform read operations using the find() and findOne() methods.

The find() method returns a cursor object which the mongo shell iterates to print documents on screen. By default, mongo prints the first 20. The mongo shell will prompt the user to “Type it” to continue iterating the next 20 results.

The following table provides some common read operations in the mongo shell:

coll = db.users;
coll.find( { name: "Joe" } );

coll = db.users;
coll.find( { }, { name: true } );

coll = db.users;
coll.find().sort( { name: 1 } );

coll = db.users;
coll.findOne( { name: "Joe" } );

See Query Documents documentation for more information and examples. See Query and Projection Operators to specify other query operators.

Error Checking Methods¶

The mongo shell write method integrates the Write Concern directly into the method execution, and returns a WriteResult() object that contains the results of the operation, including any write errors and write concern errors.

Administrative Command Helpers¶

The following table lists some common methods to support database administration:

See also administrative database methods for a full list of methods.

Opening Additional Connections¶

You can create new connections within the mongo shell.

The following table displays the methods to create the connections:

db = connect("<host><:port>/<dbname>")

conn = new Mongo()
db = conn.getDB("dbname")

See also Opening New Connections for more information on the opening new connections from the mongo shell.

Miscellaneous¶

The following table displays some miscellaneous methods:

Additional Resources¶

Consider the following reference material that addresses the mongo shell and its interface:

• mongo
• mongo Shell Methods
• Database Commands
• Aggregation Reference
• Getting Started Guide

Additionally, the MongoDB source code repository includes a jstests directory which contains numerous mongo shell scripts.