MongoDB.md

MongoDB.md

MongoDB CRUD Operations

Geospatial Queries

Geospatial Data

GeoJSON Objects

Point

{ type: "Point", coordinates: [ lng, lat ] }

LineString

{ type: "LineString", coordinates: [ [ 40, 5 ], [ 41, 6 ] ] }

Polygon

Polygons with a Single Ring

{
  type: "Polygon",
  coordinates: [ [ [ 0 , 0 ] , [ 3 , 6 ] , [ 6 , 1 ] , [ 0 , 0  ] ] ]
}

Polygons with Multiple Rings

{
  type : "Polygon",
  coordinates : [
     [ [ 0 , 0 ] , [ 3 , 6 ] , [ 6 , 1 ] , [ 0 , 0 ] ],
     [ [ 2 , 2 ] , [ 3 , 3 ] , [ 4 , 2 ] , [ 2 , 2 ] ]
  ]
}

MultiPoint

{
  type: "MultiPoint",
  coordinates: [
     [ -73.9580, 40.8003 ],
     [ -73.9498, 40.7968 ],
     [ -73.9737, 40.7648 ],
     [ -73.9814, 40.7681 ]
  ]
}

MultiLineString

{
  type: "MultiLineString",
  coordinates: [
     [ [ -73.96943, 40.78519 ], [ -73.96082, 40.78095 ] ],
     [ [ -73.96415, 40.79229 ], [ -73.95544, 40.78854 ] ],
     [ [ -73.97162, 40.78205 ], [ -73.96374, 40.77715 ] ],
     [ [ -73.97880, 40.77247 ], [ -73.97036, 40.76811 ] ]
  ]
}

MultiPolygon

{
  type: "MultiPolygon",
  coordinates: [
     [ [ [ -73.958, 40.8003 ], [ -73.9498, 40.7968 ], [ -73.9737, 40.7648 ], [ -73.9814, 40.7681 ], [ -73.958, 40.8003 ] ] ],
     [ [ [ -73.958, 40.8003 ], [ -73.9498, 40.7968 ], [ -73.9737, 40.7648 ], [ -73.958, 40.8003 ] ] ]
  ]
}

GeometryCollection

{
  type: "GeometryCollection",
  geometries: [
     {
       type: "MultiPoint",
       coordinates: [
          [ -73.9580, 40.8003 ],
          [ -73.9498, 40.7968 ],
          [ -73.9737, 40.7648 ],
          [ -73.9814, 40.7681 ]
       ]
     },
     {
       type: "MultiLineString",
       coordinates: [
          [ [ -73.96943, 40.78519 ], [ -73.96082, 40.78095 ] ],
          [ [ -73.96415, 40.79229 ], [ -73.95544, 40.78854 ] ],
          [ [ -73.97162, 40.78205 ], [ -73.96374, 40.77715 ] ],
          [ [ -73.97880, 40.77247 ], [ -73.97036, 40.76811 ] ]
       ]
     }
  ]
}

Legacy Coordinate Pairs

Geospatial Indexes

2dsphere

2d

Geospatial Indexes and Sharded Collections

Covered Queries

Geospatial Queries

Geospatial Query Operators

Geospatial Aggregation Stage

Geospatial Models

BSON Data Types

Each BSON type has both integer and string identifiers as listed in the following table:

Type	Number	Alias	Notes
Double	1	“double”
String	2	“string”
Object	3	“object”
Array	4	“array”
Binary data	5	“binData”
Undefined	6	“undefined”	Deprecated.
ObjectId	7	“objectId”	new ObjectId
Boolean	8	“bool”
Date	9	“date”	The mongo shell provides various methods to return the date, either as a string or as a Date object: - Date() method which returns the current date as a string. - new Date() constructor which returns a Date object using the ISODate() wrapper. - ISODate() constructor which returns a Date object using the ISODate() wrapper.
Null	10	“null”
Regular Expression	11	“regex”
DBPointer	12	“dbPointer”	Deprecated.
JavaScript	13	“javascript”
Symbol	14	“symbol”	Deprecated.
JavaScript (with scope)	15	“javascriptWithScope”
32-bit integer	16	“int”	NumberInt()
Timestamp	17	“timestamp”
64-bit integer	18	“long”	NumberLong("2090845886852")
Decimal128	19	“decimal”	NumberDecimal("1000.55")
Min key	-1	“minKey”
Max key	127	“maxKey”

Check Types in the mongo Shell

• instanceof
• typeof

Shell Methods

# to stop the mongodb service
net stop MongoDB

# start the mongo service
mongod

# to change the default directory
mongod --dbpath "C:\data\db"

# start MongoDB shell using the non-default MongoDB Server port
mongo --port

# print the working db
db

Collection

Cursor

Database

Query Plan Cache

Bulk Write Operation

Name	Description
Bulk.find.upsert()	Specifies upsert: true for an update operation.

User Management

Name	Description
db.auth()	Authenticates a user to a database.
db.changeUserPassword()	Changes an existing user’s password.
db.createUser()	Creates a new user.
db.dropUser()	Removes a single user.
db.dropAllUsers()	Deletes all users associated with a database.
db.getUser()	Returns information about the specified user.
db.getUsers()	Returns information about all users associated with a database.
db.grantRolesToUser()	Grants a role and its privileges to a user.
db.removeUser()	Deprecated. Removes a user from a database.
db.revokeRolesFromUser()	Removes a role from a user.
db.updateUser()	Updates user data.
passwordPrompt()	Prompts for the password as an alternative to specifying passwords directly in various mongo shell user authentication/management methods.

Role Management

Replication

Sharding

Free Monitoring

Constructors

Connection

Native

Client-Side Field Level Encryption

Command Helpers

Help Methods and Commands	Description
help	Show help.
db.help()	Show help for database methods.
db.<collection>.help()	Show help on collection methods. The <collection> can be the name of an existing collection or a non-existing collection.
show dbs	Print a list of all databases on the server.
show databases	Print a list of all available databases.
use <db>	Switch current database to <db>. The mongo shell variable db is set to the current database.
show collections	Print a list of all collections for current database.
show users	Print a list of users for current database.
show roles	Print a list of all roles, both user-defined and built-in, for the current database.
show profile	Print the five most recent operations that took 1 millisecond or more. See documentation on the database profiler for more information.
load()	Execute a JavaScript file. See Write Scripts for the mongo Shell for more information.

Collection Methods

Name	Syntax	Example
db.collection.insert()	db.collection.insert( <document or array of documents>, { writeConcern: <document>, ordered: <boolean> } )
db.collection.insertOne()	db.collection.insertOne( <document>, { writeConcern: <document> } )
db.collection.insertMany()	db.collection.insertMany( [ <document 1> , <document 2>, ... ], { writeConcern: <document>, ordered: <boolean> } )
db.collection.find()	db.collection.find( <query>, <projection> )	db.bios.find( { birth: { $gt: new Date('1920-01-01') }, death: { $exists: false } } , { firstName: 1, lastname:1, _id: 0 } )
db.collection.findOne()	db.collection.findOne( <query>, <projection> )	db.bios.findOne({ $or: [ { 'name.first' : /^G/ }, { birth: { $lt: new Date('01/01/1945') } } ] })
db.collection.updateOne()	db.collection.updateOne( <filter>, <update>, { upsert: <boolean>, writeConcern: <document>, collation: <document>, arrayFilters: [ <filterdoc1>, ... ], hint: <document|string> } )	db.restaurant.updateOne( { "name" : "Central Perk Cafe" }, { $set: { "violations" : 3 } } );
db.collection.updateMany()	db.collection.updateMany( <filter>, <update>, { upsert: <boolean>, writeConcern: <document>, collation: <document>, arrayFilters: [ <filterdoc1>, ... ], hint: <document|string> } )
db.collection.update()	db.collection.update( <query>, <update>, { upsert: <boolean>, multi: <boolean>, writeConcern: <document>, collation: <document>, arrayFilters: [ <filterdoc1>, ... ], hint: <document|string> } )	db.books.update( { item: "ZZZ135" }, { item: "ZZZ135", stock: 5, tags: [ "database" ] }, { upsert: true } )
db.collection.replaceOne()	db.collection.replaceOne( <filter>, <replacement>, { upsert: <boolean>, writeConcern: <document>, collation: <document>, hint: <document|string> } )
db.collection.deleteOne()	db.collection.deleteOne( <filter>, { writeConcern: <document>, collation: <document> } )
db.collection.deleteMany()	db.collection.deleteMany( <filter>, { writeConcern: <document>, collation: <document> } )
db.collection.remove()	db.collection.remove( <query>, { justOne: <boolean>, writeConcern: <document>, collation: <document> } )

Database Methods

Name	Syntax	Description
db.createCollection()	db.createCollection( <name>, { capped: <boolean>, autoIndexId: <boolean>, size: <number>, max: <number>, storageEngine: <document>, validator: <document>, validationLevel: <string>, validationAction: <string>, indexOptionDefaults: <document>, viewOn: <string>, pipeline: <pipeline>, collation: <document>, writeConcern: <document> } )	Creates a new collection or a view. Commonly used to create a capped collection.
db.dropDatabase()		Removes the current database.
db.runCommand()		Runs a database command.
db.shutdownServer()		Shuts down the current mongod or mongos process cleanly and safely.
db.stats()		Returns a document that reports on the state of the current database.

Cursor Methods

Name	Description
cursor.pretty()	Configures the cursor to display results in an easy-to-read format.
cursor.count()	Modifies the cursor to return the number of documents in the result set rather than the documents themselves.
cursor.limit()	Constrains the size of a cursor’s result set.
cursor.forEach()	Applies a JavaScript function for every document in a cursor.
cursor.map()	Applies a function to each document in a cursor and collects the return values in an array.
cursor.next()	Returns the next document in a cursor.
cursor.hasNext()	Returns true if the cursor has documents and can be iterated.
cursor.skip()	Returns a cursor that begins returning results only after passing or skipping a number of documents.
cursor.sort()	Returns results ordered according to a sort specification.
cursor.toArray()	Returns an array that contains all documents returned by the cursor.

Operators

Query and Projection Operators

Query Selectors

Comparison (Query Selectors)

Name	Verbose	Description
$eq	equal	Matches values that are equal to a specified value.
$ne	not equal	Matches all values that are not equal to a specified value.
$gt	greater than	Matches values that are greater than a specified value.
$gte	greater than or equal	Matches values that are greater than or equal to a specified value.
$lt	less than	Matches values that are less than a specified value.
$lte	less than or equal	Matches values that are less than or equal to a specified value.
$in	in array	Matches any of the values specified in an array.
$nin	not in array	Matches none of the values specified in an array.

Logical (Query Selectors)

Name	Description
$and	Joins query clauses with a logical AND returns all documents that match the conditions of both clauses.
$or	Joins query clauses with a logical OR returns all documents that match the conditions of either clause.
$not	Inverts the effect of a query expression and returns documents that do not match the query expression.
$nor	Joins query clauses with a logical NOR returns all documents that fail to match both clauses.

Element (Query Selectors)

Name	Description
$exists	Matches documents that have the specified field.
$type	Selects documents if a field is of the specified type.

Evaluation (Query Selectors)

Name	Description
$expr	Allows use of aggregation expressions within the query language.
$jsonSchema	Validate documents against the given JSON Schema.
$mod	Performs a modulo operation on the value of a field and selects documents with a specified result.
$regex	Selects documents where values match a specified regular expression.
$text	Performs text search.
$where	Matches documents that satisfy a JavaScript expression.

Geospatial (Query Selectors)

Name	Description
$geoIntersects	Selects geometries that intersect with a GeoJSON geometry. The 2dsphere index supports $geoIntersects.
$geoWithin	Selects geometries within a bounding GeoJSON geometry. The 2dsphere and 2d indexes support $geoWithin.
$near	Returns geospatial objects in proximity to a point. Requires a geospatial index. The 2dsphere and 2d indexes support $near.
$nearSphere	Returns geospatial objects in proximity to a point on a sphere. Requires a geospatial index. The 2dsphere and 2d indexes support $nearSphere.

Array (Query Selectors)

Name	Description
$all	Matches arrays that contain all elements specified in the query.
$elemMatch	Selects documents if element in the array field matches all the specified $elemMatch conditions.
$size	Selects documents if the array field is a specified size.

Bitwise (Query Selectors)

Comments (Query Selectors)

Name	Description
$comment	Adds a comment to a query predicate.

Projection Operators

Name	Description
$	Projects the first element in an array that matches the query condition.
$elemMatch	Projects the first element in an array that matches the specified $elemMatch condition.
$meta	Projects the document’s score assigned during $text operation.
$slice	Limits the number of elements projected from an array. Supports skip and limit slices.

Update Operators

Fields

Name	Description
$set	Sets the value of a field in a document.
$unset	Removes the specified field from a document.
$inc	Increments the value of the field by the specified amount.
$min	Only updates the field if the specified value is less than the existing field value.
$max	Only updates the field if the specified value is greater than the existing field value.
$mul	Multiplies the value of the field by the specified amount.
$rename	Renames a field.

Array

Operators

Name	Description
$	Acts as a placeholder to update the first element that matches the query condition.
$[]	Acts as a placeholder to update all elements in an array for the documents that match the query condition.
$[<identifier>]	Acts as a placeholder to update all elements that match the arrayFilters condition for the documents that match the query condition.
$push	Adds an item to an array.
$addToSet	Adds elements to an array only if they do not already exist in the set.
$pull	Removes all array elements that match a specified query.
$pullAll	Removes all matching values from an array.
$pop	Removes the first or last item of an array.

Modifiers

Name	Description
$each	Modifies the $push and $addToSet operators to append multiple items for array updates.
$slice	Modifies the $push operator to limit the size of updated arrays.

$position | Modifies the $push operator to specify the position in the array to add elements.

$sort | Modifies the $push operator to reorder documents stored in an array.

Aggregation Pipeline Stages

Aggregation Pipeline Operators

Arithmetic Expression Operators

Array Expression Operators

Boolean Expression Operators

Comparison Expression Operators

Conditional Expression Operators

Date Expression Operators

Literal Expression Operator

Object Expression Operators

Set Expression Operators

String Expression Operators

Text Expression Operator

Trigonometry Expression Operators

Type Expression Operators

Accumulators ($group)

Accumulators (in Other Stages)

Variable Expression Operators

Query Modifiers