• It is an open source initiative
• It is a NoSQL database (Not only SQL, it does not go against SQL, only that it proposes a different way of handling the information)
• Database focused on handling large amounts of data
• Oriented to document storage
• It comes from the term humongous (which means giant)
• Mongo is flexible and scalable (More resources can be added simply by adding more servers, usually known as a cluster)
• It is written in C ++
• Easy change of production scheme
• It is possible to run JS on the mongo server
• Mongo is documents oriented
• Each record in mongo is a document
• Mongo is schemales
• Provides easy horizontal scaling
• The data format of the documents is JSON
• The data types of the documents are the same as those handled in javascript!

• mongod (initialize the database server) "server"
• mongo (connects to the database) "client"

• Database
• Collections (it is the division within the database, it resembles the tables in SQL)
• Documents (they are the records in JSON format that are stored for the collections)

• My application will have a very fast growth
• My application will have servers in the cloud
• I want to mount a database as fast as possible
• My data will not always have the same structure
• The information will be very dynamic
• you will have many users accessing at the same time

• show dbs -> (shows databases)
• db -> (shows current database)
• db.help-> (shows all the methods that can be used with mongoDB)
• use <databse>-> (create a database and switch to it, only use it temporarily, but actually create it only when at least 1 record is inserted)
• db.dropDatabase ()-> drops the current database, it is important to run db first to ensure that it is the database to drop.

• show collections -> (see db collections)
• db.createCollections ("name")-> creates a collection within the current db
• db.<collectionName>.drop() (drops the collectionName collection within the current db)

Find

• find all documents in the products collection (pretty organize the output format)

db.products.find().pretty()

• Search for a field

db.products.find( { "nameProduct" : "valueToFind" } )

• Find those that are not equal to a certain value

db.products.find( { "nameProduct" : { $ne : "Keyboard"} } )

• Search for two fields

db.products.find( { "field1" : "value1" , "field2": "value2"})

• When I need to search only some properties of the document. If I want to exclude any field in the result "field1": 0

db.products.find( { "field1" : "value1" } , { "_id" : 0, "field1": 1 } )

• Query and order the result asc

db.products.find( { "field1" : "value1" } ).sort( { field : 1 } )

• Query and order the result desc

db.products.find( { "field1" : "value1" } ).sort( { field : -1 } )

• Total records

db.products.count()

• In mongo you can execute functions, for example (bring the registers and go through them 1 by 1):

db.products.find().forEach(product -> print( "Product Name " + product.name ))

• creates a document in the products collection, if the collection does not exist mongo creates it

db.products.insert( {"nameProduct": "Laptop"})

Note: When a record is stored in mongo, what mongo does is convert that object into BSON format (JSON Binary to optimize the query and other operations on the data)

• Create multiple documents

db.products.insert([ { "nameProdct" : "Keyboard", "price": "22"	} , { "nameProduct": "Laptop", "price": "200"	} ] )

• update a document, replace the entire record

db.products.update( { "field" : "value" }, { "price" : 99.99 } )

• update various document attributes

db.products.update( { "field" : "value" }, { "price" : 99.99, "name" : "value" } )

• $set updates an existing field, or if it doesn't exist it creates it

db.products.update({"name" : "laptop"} , { $set : { "description" : "value" } } )

• If it is required to update a record and it has not been created, it can be created as follows

db.product.update( { "name" : "desktop" } , { $set: { "description" : "gaming desktop" } }, { upset: true } )

• If you need to change the name of any property you can use rename

db.products.update( { "name" : "desktop" } , { $rename : { "name" : "nombre" } } )

• If I want to delete a field I can use unset

db.employee.update ( { "name" : "Alejo"} , { $unset : { edad : 1 } } )

• To delete a record, use remove

db.products.remove( { "name" : "valor" } )

• If you need to delete everything, the search json is left empty db.products.remove( { } )

• $gt > greater than
• $gte >= greater than equals
• $lt < less than
• $lte <= less than equals

• To implement the 1 to many relationship in mongo, arrays are used
• Occurs when an array can store a document

var array = [1, 2, 3]
var user= { "name": "Alejo1"  values : array }
db.users.insert( user )

• Search if the element exists and if not add it ($addToSet)

db.users.update ( { } , $addToSet: { values: 4} })

• if required add the value regardless of whether it exists ($push)

db.users.update( { } , { $push: { values: 4 } } )

• if you want to enter multiple values

db.users.update( { } , { $push: { values: { $each : [ 5 , 6] } } } )

• if you want to enter multiple values

db.users.update( { } , { $addToSet: { values: { $each : [ 5, 6] } } } )

• insert at a specific position

db.usuarios.update( { } , { $addToSet: { values: { $each : [ 8, 9] , $position: 4 } } } )

• if after inserting you need to order

db.usuarios.update( { } , { $addToSet: { values: { $each : [ 10, 11] , $sort:1 } } } )

• indicate to apply the changes if it finds multiple records

db.employee.update({ age: { $gte : 28 }} , { $set : { level2: 2 } } , { multi:true } )