I've got a NodeJS/Express/MongoDB
app. For one of my endpoints I'm trying to get some stats from the database and I'm having trouble doing it using promises.
I know that db doesn't get moved between the different .thens
but no matter how I re-arrange the code I can't get anything out of the console.log()
except the first users count. I've also tried saving db into a variable declared at the start of the function but that doesn't help either.
What's the proper way to make multiple queries to MongoDB in a promisified way?
Node Code:
function getStats(num){
var stats = "";
MongoClient.connect(`${mongoString}/SiteUsers`)
.then(db => {
db.db().collection("Users").find({}).count()
.then( userCount => {
stats += `Users: ${userCount}\n`
return db;
})
.then( adminCount => {
db.db().collection("Users").find({admin:true}).count()
.then( adminCount => {
stats += `Admins: ${adminCount}\n`
})
})
.then( data => {
console.log(`Stats are now: \n${stats}`);
})
})
.catch(err => {
if(err) console.log(err);
});
}
Thanks!
There are several ways that you can handle the order of your promises. One of which is to use async/await functionality.
async function getStats(num){
try {
const conn = await MongoClient.connect(`${mongoString}/SiteUsers`)
const userCount = await conn.db().collection("Users").find({}).count()
const adminCount = await conn.db().collection("Users").find({admin:true}).count()
console.log(`User count: ${userCount}\nAdmin count: ${adminCount}`)
} catch (err) {
console.log(err)
}
}
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