複数の mongodb に接続する例

test5_mongo2.js

//
// mongo , mongo2 の接続
// 複数の mongodb に接続する例
// 
var ObjectID = require('mongodb').ObjectID;
const MongoClient = require('mongodb').MongoClient;
var moment = require('moment')

//
async function test1(){
    var bread_order= []
    try{
        let client = await MongoClient.connect( "mongodb://mongo2:27017" );
//        let client = await MongoClient.connect( "mongodb://localhost:27018" );
        const db = client.db("db1");
        await db.collection("books").find().toArray().then((docs) => {
                bread_order = docs
        }).then(() => {
            client.close();
        });        
console.log( bread_order );
    } catch (err) {
        console.log(err);
    }
}
//
async function test2(){
    var orders= []
    try{
        // connect localhost
        let client = await MongoClient.connect( "mongodb://localhost:27018" );
        const db = client.db("db1");
        await db.collection("orders").find().toArray().then((docs) => {
            orders = docs
        }).then(() => {
            client.close();
        });        
console.log( "orders.length :", orders.length );
        // connect mongo2
        books = []
        let client_2 = await MongoClient.connect( "mongodb://mongo2:27017" );
        let db_2 = client_2.db("db1");
        await db_2.collection("books").find().toArray().then((docs) => {
            books = docs
        }).then(() => {
            client_2.close();
        });        
        console.log( "books.length :", books.length );
    } catch (err) {
        console.log(err);
    }
}

/*********************************
 * main
***********************************/
test2()