/MongoExercise

Tutorials for getting a MongoDb up and running with the latest to start seeding and generating data

Primary LanguageMakefile

MongoDB Exercise

The exercise of this is to put together a bunch of tutorials on setting up Mongo to use locally, in the cloud and in Docker so that I can TDD an API solution in another branch.

Environment

The point of this exercise is to have MongoDB ready to play with and create and delete database records. So make sure you have docker setup. There is a docker-compose file in the root ready to start, or if you are on a. mac, there is a Makefile in the root for you easilly get the image generated using:

mdb-up:
	echo "Starting Mongo ..."
	docker compose -f docker-compose.yml up

mdb-up-detached:
	echo "Starting Mongo ..."
	docker compose -f docker-compose.yml up

mdb-down:
	echo "Stopping Mongo ..."
	docker compose -f docker-compose.yml up -d

mdb-verify:
	echo "Verify Docker script ..."
	docker compose -f docker-compose.yml config

Feel free to alter the script to experiment with whatever you need.

Tutorials and exercises

  • Start up mongo

  • Navigate to http://localhost:8081/

    image-20211224182529583

  • Use the interface to create a database manually and experiment utilising the basic UI for fun

  • GUI client's for connecting to Mongo (MongoExpress, DataGrip, MongoDB and Compass)

  • Mongo Shell is not graphical and can be used through command line

    mongo mongodb://localhost:27017 -u rootuser -p rootpass

  • Connect to the docker cli for mongdb or do it through the terminal direct if you are familiar with docker

    image-20211225114207850

  • Execute the Mongo Shell command from above and once connected execute show dbs; to get a list of the databases

    image-20211225114550673

  • Create a database on Mongo Express using the UI, and than type use <database>; to connect to the database and db.getName(); make sure you are connected to the database by name

  • Create a collectiondb.createCollection("<collectionSingular>"); and then show collections;

  • Deleting the collection db.player.drop();

  • Finally getting the stats on the collection db.player.stats(); can give you everything about the details if that collection, as well as help on methods

  • Deleting the database can be done with db.dropDatabase();

  • Help on all other commands db.help(); will give you every command you need

    image-20211226102337319

  • Find is potentially made up the collection, a query, projection of not all fields

    db.player.find({name: {$eq: "Killa"}}, { name: 1})

    • Find everyone db.player.find({})

    image-20211226123252758

    • Cursor modifiers are ways of filtering the data returned one more step like limit e.g. db.find(...).limit(5) to return 5 records only

  • Update follows the same patterns as all except it contains a $set for the values you want to update e.g.

    # Example of incrementing specific players battle count, losses and totalWinnings
db.player.update({_id: ObjectId("61c85ee6825383f6c0897182"), {$set: {$inc: {battles:1} , $inc: {losses: 0}, $inc: {totalWinnings: 350}}})

    • $unset to remove field which can be useful if there is a need to remove an unecessary field

      # Example of deleting the bountyValue field
db.player.update({{_id: ObjectId("61c85ee6825383f6c0897182"), {$unset: {bountyValue: 1}}}})
# or update bounty Value for all players
db.player.updateMany({}, {$unset: {bountyValue: 1}})

  • Here is a very good cheat sheet to keep handy when trying some other Mongo commands

    image-20211226104557042

    Connecting with Compass or vscode

  • Install Mongo as a vscode extension

  • With default settings, connect to the database using mongodb://rootuser:rootpass@localhost:27017/<database>

    image-20211227141316539

    Basics

  • Cap Theorem knowledge and why to use NoSQL and what to do to configure it

    • Scaling mongo in detail, and is one of the most important reasons to choose NOSQL over relational databases. If you understand this, the principle of distributed computing, you will understand why you chose one over another

  • Mongo stores records as BSON documents, which is a binary representation of JSON

  • BSON Types (with deprecated types removed)

    Type Number Alias Notes
    Double 1 "double"
    String 2 "string"
    Object 3 "object"
    Array 4 "array"
    Binary data 5 "binData"
    ObjectId 7 "objectId"
    Boolean 8 "bool"
    Date 9 "date"
    Null 10 "null"
    Regular Expression 11 "regex"
    JavaScript 13 "javascript"
    32-bit integer 16 "int"
    Timestamp 17 "timestamp"
    64-bit integer 18 "long"
    Decimal128 19 "decimal" New in version 3.4.
    Min key -1 "minKey"
    Max key 127 "maxKey"

  • If you are familiar with SQL server, these are the NOSQL Mongo specific comparisons found at https://docs.mongodb.com/manual/reference/sql-comparison/

  • Here is a comprehensive cheat sheet for going through the basics

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