How to list all indexes of Mongo Collection with MongoDB Node native?

Question

Well I wanna know how I can fetch all indexes from a specific collection of mongodb. I trying with listIndexes, indexes and indexInformation, but these methods only give me empty values(array and object), but if I execute db.getCollection('truck').getIndexes() on mongo terminal, this give me all indexes.

I think maybe this is a bug, but I don't find any information about this, so let me show my examples and a screenshot from "Robo 3T".

await connection.collection('truck').indexes() // returns []
await connection.collection('truck').listIndexes().toArray() // returns []
await connection.collection('truck').indexInformation() // returns {}

So... Whats happend here? why these methods not working well?

Thanks :D

P.S: I'm using mongodb version 3.5.5: https://github.com/mongodb/node-mongodb-native

score 7 · Answer 1 · answered Mar 18 '20 at 02:02

7

Looks like in the code await connection.collection('truck').indexes() you need to specify the database also. It is not clear what is connection.

The following script will print the indexes in the specified database and collection.

const MongoClient = require('mongodb').MongoClient;

( async function() {
     const client = new MongoClient('mongodb://localhost:27017', { useNewUrlParser: true, useUnifiedTopology: true } );
     try {
        await client.connect();
        const coll = client.db('test').collection('books');
        const indxs = await coll.indexes();
        console.log(indxs);     // prints all the indexes
     } catch (err) {
         console.log(err.stack);
     }
     client.close();
)();

answered Mar 18 '20 at 02:02

prasad_

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But I specified the database... The problem is not about db :'( – Olaf Erlandsen Mar 18 '20 at 02:04
What was the problem? – prasad_ Mar 18 '20 at 02:06
I think the problem is the driver cos' I try the same with python and nodejs but... this not work. After try another thinks I found the solution: using `command`. Show my answer :D – Olaf Erlandsen Mar 18 '20 at 02:11

Olaf Erlandsen · Accepted Answer · 2020-03-18T02:15:59.210

Well, after try some solutions like move language from javascript to Python and using Pymongo... and getting the same result... I decided using command interface but usin the native api in driver... Yep, I using command, let me show how:

import {MongoClient} from 'mongodb'
const client = await MongoClient.connect("...")
const db = client.db("MyOwnDatabase")

// the next line retrieve empty array
db.collection('truck').indexes();

// the next line retrieve all indexes 
db.command({listIndexes: "truck"}).cursor.firstBatch;

In Python is too similar:

import pymongo
client = pymongo.MongoClient("...")
db = client.MyOwnDatabase

# retrieve empty object
db.truck.index_information()

# retrieve all indexes 
db.command("listIndexes", "truck")

I think this problem is about the driver... both are official driver, but none works well :D

P.S: I know this question is about javascript, but I found the same problem in Python and this is the solution for both.

`db.truck.indexes();`. What is `truck`? – prasad_ Mar 18 '20 at 02:14 — prasad_, Mar 18 '20 at 02:14
`truck` is the collection. I lost `collection(...)` – Olaf Erlandsen Mar 18 '20 at 02:16 — Olaf Erlandsen, Mar 18 '20 at 02:16

score 1 · Answer 3 · answered Mar 18 '20 at 08:27

1

listIndexes is a database command, you have to call it like this:

db.runCommand( {listIndexes: "truck"} )

or using the shorthand

db.truck.getIndexes()
db.collection('truck').getIndexes()

Method indexInformation does not exist in MongoDB (at least I did not find it). collection.indexes() I did not find either.

answered Mar 18 '20 at 08:27

Wernfried Domscheit

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Well I think you may need read the question and my answer. Thanks – Olaf Erlandsen Mar 18 '20 at 12:30

score 1 · Answer 4 · answered Aug 10 '20 at 11:17

1

...for prettier output:

for ( var i=0; i < indxs.length; i++ ) {
    console.log(indxs[i].ns + '.' + indxs[i].name,'key(s):-\n',indxs[i].key);
}

answered Aug 10 '20 at 11:17

Donald W Garton

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A full example is missing here. – Timo May 16 '22 at 12:50

score 0 · Answer 5 · answered May 16 '22 at 12:53

Working Example in Nodejs with `indexes()`

a) Definition

export function getIndexes(coll, callback: Function) {
MongoClient.connect(process.env.uri, (err, db) => {
    db.db(dbWeb).collection(coll).indexes( (err, res) => {
        callback(res)
        db.close();
    })
})

}

b) Call

export function getIndexes(coll) { mongo[arguments.callee.name](coll, res => { console.log(res) }) }

How to list all indexes of Mongo Collection with MongoDB Node native?

5 Answers5

Working Example in Nodejs with indexes()

Working Example in Nodejs with `indexes()`