#Day71 of #100DaysOfCode
Today the loooonnng weekend ended 
so it was a little stressful day, thinking of all the work I have ahead of me 
Today I spent time working on multiple things, Realm, MongoDB, and my Node.js message-mixer app to learn module exports and require functions.
On MongoDB front, I wanted to understand how to define JSON schema but I was not able to figure that out, so I had to enable development mode On for my realm app, add a new class to my application and then sync to Atlas and that will auto-generate the schema on cloud. I am working on Restaurant App using Atlas Sync .
POJO class:
open class Borough (
@PrimaryKey
var _id: ObjectId = ObjectId(),
var borough: String? = null,
var _partition: String = "borough"
): RealmObject() {
}
MongoDB Schema generated on Cloud
{
"title": "Borough",
"bsonType": "object",
"required": [
"_id",
"_partition"
],
"properties": {
"_id": {
"bsonType": "objectId"
},
"borough": {
"bsonType": "string"
},
"_partition": {
"bsonType": "string"
}
}
}
I also learned I cannot run distinct query from MongoDB Compass but I can execute it on mongo shell. Another thing I learned was the connection to shell does not happen with any other database than test . For this I think I will have to ask the expert 
MongoDB shell version v4.4.1
Enter password:
connecting to: mongodb://**<truncated>**.mongodb.net:27017, **<truncated>**.mongodb.net:27017, **<truncated>**.mongodb.net:27017/database?authSource=admin&compressors=disabled&gssapiServiceName=**<truncated>**
{"t":{"$date":"2022-04-18T15:08:07.345Z"},"s":"I", **<truncated>**,
"msg":"RSM host selection timeout",
"error":"FailedToSatisfyReadPreference: Could not find host matching read preference { mode: \"nearest\" } for set atlas-nudr3h-shard-0"}}
*** It looks like this is a MongoDB Atlas cluster. Please ensure that your IP whitelist allows connections from your network.
Error: connect failed to replica set **<truncated>**
connect@src/mongo/shell/mongo.js:374:17
@(connect):2:6
exception: connect failed
exiting with code 1
I found distinct boroughs and made a separate collection for them in the restaurant database
db.restaurants.distinct("borough")
[
"Bronx",
"Brooklyn",
"Manhattan",
"Missing",
"Queens",
"Staten Island"
]
db.Borough.insertMany([{borough:"Bronx"},{borough:"Brooklyn"},{borough:"Manhattan"}])
db.Borough.find({})
{ "_id" : ObjectId("625d9151be17483a1e2ac403"), "borough" : "Bronx" }
{ "_id" : ObjectId("625d9151be17483a1e2ac404"), "borough" : "Brooklyn" }
{ "_id" : ObjectId("625d9151be17483a1e2ac405"), "borough" : "Manhattan" }
{ "_id" : ObjectId("625d91b4be17483a1e2ac406"), "borough" : "Missing" }
{ "_id" : ObjectId("625d91b4be17483a1e2ac407"), "borough" : "Queens" }
{ "_id" : ObjectId("625d91b4be17483a1e2ac408"), "borough" : "Staten Island" }
On the node js front, I managed to find the error that I was facing with the module.exports. I had to type this dot function name to refer it than calling it without the keyword.
Also, the stack overflow answer helped me figure out, I am calling the function incorrectly.
I added the challenge code to Github as it was an interesting Encryption challenge
Until tomorrow 