Do I need to connect to Mongo over and over again? - mongodb

Question

I am making a discord bot. When I was using java, I saved the data to mongo by creating different databases for each server my bot is in but on javascript I can only use one database.
And the only database it lets me connect/see is test database, other than that it shows everything as undefined.
And Mongo js docs tell me to connect to database over and over again but when using java I just connected on bot launch and was able to use it whenever I want. I tried all the examples I could find on stackoverflow but none of them helped me at all.
app.js :
require("./handler/mongo")();
client.on("ready", () => {
console.log(global.mongoclient.db("574612262275252231").collection("settings").find({}));
}
mongo.js:
const mongo = require('mongodb').MongoClient;
module.exports = function(){
mongo.connect(uri, (err, client) => {
if(err) throw err;
global.mongoclient = client;
console.log("a");
});
}
console output:
a
Cursor {
_readableState: ReadableState {
objectMode: true,
highWaterMark: 16,
buffer: BufferList { head: null, tail: null, length: 0 },
length: 0,
pipes: [],
flowing: null,
ended: false,
endEmitted: false,
reading: false,
sync: true,
needReadable: false,
emittedReadable: false,
readableListening: false,
resumeScheduled: false,
errorEmitted: false,
emitClose: true,
autoDestroy: false,
destroyed: false,
defaultEncoding: 'utf8',
awaitDrainWriters: null,
multiAwaitDrain: false,
readingMore: false,
decoder: null,
encoding: null,
[Symbol(kPaused)]: null
},
readable: true,
_events: [Object: null prototype] {},
_eventsCount: 0,
_maxListeners: undefined,
operation: FindOperation {
options: {
skip: 0,
limit: 0,
raw: undefined,
hint: null,
timeout: undefined,
slaveOk: true,
readPreference: [ReadPreference],
db: [Db],
promiseLibrary: [Function: Promise]
},
ns: MongoDBNamespace {
db: '574612262275252231',
collection: 'settings'
},
cmd: {
find: '574612262275252231.settings',
limit: 0,
skip: 0,
query: {},
raw: undefined,
hint: null,
timeout: undefined,
slaveOk: true,
readPreference: [ReadPreference]
},
readPreference: ReadPreference { mode: 'primary', tags: undefined },
cursorState: {
cursorId: null,
cmd: [Object],
documents: [],
cursorIndex: 0,
dead: false,
killed: false,
init: false,
notified: false,
limit: 0,
skip: 0,
batchSize: 1000,
currentLimit: 0,
transforms: undefined,
raw: undefined
}
},
pool: null,
server: null,
disconnectHandler: undefined,
bson: undefined,
ns: '574612262275252231.settings',
namespace: MongoDBNamespace { db: '574612262275252231', collection: 'settings' },
cmd: {
find: '574612262275252231.settings',
limit: 0,
skip: 0,
query: {},
raw: undefined,
hint: null,
timeout: undefined,
slaveOk: true,
readPreference: ReadPreference { mode: 'primary', tags: undefined }
},
options: {
skip: 0,
limit: 0,
raw: undefined,
hint: null,
timeout: undefined,
slaveOk: true,
readPreference: ReadPreference { mode: 'primary', tags: undefined },
db: Db {
_events: [Object: null prototype] {},
_eventsCount: 0,
_maxListeners: undefined,
s: [Object],
serverConfig: [Getter],
bufferMaxEntries: [Getter],
databaseName: [Getter],
[Symbol(kCapture)]: false
},
promiseLibrary: [Function: Promise]
},
topology: ReplSet {
_events: [Object: null prototype] {
authenticated: [Function (anonymous)],
error: [Array],
timeout: [Array],
close: [Array],
parseError: [Array],
reconnect: [Array],
commandStarted: [Function (anonymous)],
commandSucceeded: [Function (anonymous)],
commandFailed: [Function (anonymous)],
serverOpening: [Function (anonymous)],
serverClosed: [Function (anonymous)],
serverDescriptionChanged: [Function (anonymous)],
serverHeartbeatStarted: [Function (anonymous)],
serverHeartbeatSucceeded: [Function (anonymous)],
serverHeartbeatFailed: [Function (anonymous)],
topologyOpening: [Function (anonymous)],
topologyClosed: [Function (anonymous)],
topologyDescriptionChanged: [Function (anonymous)],
joined: [Function (anonymous)],
left: [Function (anonymous)],
ping: [Function (anonymous)],
ha: [Function (anonymous)],
connectionPoolCreated: [Function (anonymous)],
connectionPoolClosed: [Function (anonymous)],
connectionCreated: [Function (anonymous)],
connectionReady: [Function (anonymous)],
connectionClosed: [Function (anonymous)],
connectionCheckOutStarted: [Function (anonymous)],
connectionCheckOutFailed: [Function (anonymous)],
connectionCheckedOut: [Function (anonymous)],
connectionCheckedIn: [Function (anonymous)],
connectionPoolCleared: [Function (anonymous)],
open: [Function],
fullsetup: [Function],
all: [Function]
},
_eventsCount: 35,
_maxListeners: Infinity,
s: {
coreTopology: [ReplSet],
sCapabilities: [ServerCapabilities],
tag: undefined,
storeOptions: [Object],
clonedOptions: [Object],
store: [Store],
options: [Object],
sessionPool: [ServerSessionPool],
sessions: Set(0) {},
promiseLibrary: [Function: Promise]
},
[Symbol(kCapture)]: false
},
cursorState: {
cursorId: null,
cmd: {
find: '574612262275252231.settings',
limit: 0,
skip: 0,
query: {},
raw: undefined,
hint: null,
timeout: undefined,
slaveOk: true,
readPreference: [ReadPreference]
},
documents: [],
cursorIndex: 0,
dead: false,
killed: false,
init: false,
notified: false,
limit: 0,
skip: 0,
batchSize: 1000,
currentLimit: 0,
transforms: undefined,
raw: undefined
},
logger: Logger { className: 'Cursor' },
s: {
numberOfRetries: 5,
tailableRetryInterval: 500,
currentNumberOfRetries: 5,
state: 0,
promiseLibrary: [Function: Promise],
explicitlyIgnoreSession: false
},
[Symbol(kCapture)]: false
}

Answer 1

And Mongo js docs tell me to connect to database over and over again
Those are simply examples. You can have a global client if you like (which would make sense for real applications).