© joe mertz -m2c: building distributed applications 1 · 2017. 12. 4. · •due by wednesday (or...

©JoeMertz- M2C:BuildingDistributedApplications 1

• AnexampleofaNoSQL database• Isschema-less– Donotdefinetablesandcolumnsinadvance– Store newdatahoweverisneeded

• Stored asBSON• SimilartoJSON,butwitha fewmoredatatypes

– JSONisessentiallyserializedJavaScriptobjects» I.e. whatJavaScriptobjectswouldlooklikeifrepresentedasanobjectliteral

• ThereforeMongoDB essentiallystoresJavaScriptobjects– Easy tosaveaJavaScriptobject– Easy torestoreasaJavaScriptobject

©JoeMertz- M2C:BuildingDistributedApplications 2

• Browse comparisonon:– http://www.mongodb.org/display/DOCS/SQL+to+Mongo+Mapping+Chart

©JoeMertz- M2C:BuildingDistributedApplications 3

• ItisunclearwhetheritisbeneficialornottobethinkingintermsofRDBMSandmappingittoMongo.

• Myintuition:– ForgetaboutRDBMSinthiscase– JustseeMongo asasimplewaytostore,query,andretrieveJavaScriptobjects

©JoeMertz- M2C:BuildingDistributedApplications 4

• Database– Adatabaseisasetofcollections

• Collections– Acollectionisasetofdocuments

• Documents– Adocumentis(essentially)aJSONstring

©JoeMertz- M2C:BuildingDistributedApplications 5

• SaveandfindJSONdocuments– EachJSONdocument isnotrestricted tohavethesamestructure,buttheymostlydo

– Eachdocumenthas(globally) unique_id• ACollection isasetofJSONdocuments• ADatabaseis asetofJSONcollections

©JoeMertz- M2C:BuildingDistributedApplications 6

• What ispassedtomongodb:{"name":"apple","price":1.99}

• Mongodb addsinan_id:{"name":"apple","price":1.99,"_id":ObjectId("35414c4ebb264d7000000000")}

©JoeMertz- M2C:BuildingDistributedApplications 7

• Mongod – theMongoDB databaseserver– Listensbydefaultonport27017– Requests/responsesviaaMongoDB protocol

• Mongo– aMongoDB shellapplication– AJavaScript shelltointeractwithMongoDB– Candoalldatabaseoperations

• MongoDB drivers– Existformany languages– Providesalanguage-specificAPIforinteractingwithMongoDB

©JoeMertz- M2C:BuildingDistributedApplications 8

• Scan:– https://www.mongodb.com/who-uses-mongodb

©JoeMertz- M2C:BuildingDistributedApplications 9

• SQL and NoSQLDBMSseachhavetheirstrengths• Ourpurposein67-328:– Exposure:havebasicknowledgeofit– AneasywaytostoreandretrievedatainaformveryclosetoJavaScriptobjects(BSON)

©JoeMertz- M2C:BuildingDistributedApplications 10

• Browseto:https://docs.mongodb.com/manual/administration/install-community/

• Followthedownloadinstructions:–MacOS:IfoundinstallingHomeBrew andthenMongoDB tobeeasy.

• Experimentwithmongoshell:– Start:https://docs.mongodb.org/getting-started/shell/import-data/

– FollowtheirexamplethroughRemoveData

©JoeMertz- M2C:BuildingDistributedApplications 11

• Studio3Thasafreeversiontoview/editmongoDB databases

©JoeMertz- M2C:BuildingDistributedApplications 12

• Inthemongoshell,youcandirectlyinteractwiththemongod inaREPL.

• Tointeractwithmongod fromwithinanodeprogram,usethenpm modulemongodb:– npm installmongodb -- save

©JoeMertz- M2C:BuildingDistributedApplications 13

• Runmongodb• Runmongo• Runmongodb example

• YoucanfindtheAPIforthedemonstratedcollectionmethodsat:– http://mongodb.github.io/node-mongodb-native/2.2/api/Collection.html

©JoeMertz- M2C:BuildingDistributedApplications 14

• DuebyWednesday(orfirst10mininclass):– mLab Introduction

• DueNovember20– ImplementsimpleCRUDoperationsforwhatyouarepersistinginyourfinalproject.

– Haveatleastasinglewebpagefromwhichyoucanget,post,(put,)anddeletedocumentstoaMongoDBdatabase.

– Youdon'thavetodoallyourfinalprojectcollections,butyouneedtodoonecollectionofdocuments,andatleast3attributesperdocument.

©JoeMertz- M2C:BuildingDistributedApplications 15