Rajan Lagah

app.get('/buildings', async (req, res) => {
    try {
        await db.db('').collection('buildings').find({}).toArray(function (err, result) { // second db search in this
        await db.db('').collection('buildings').aggregate([
        {$group : {_id: "$campusName", buildings : {$push : {buildingName : "$buildingName", phoneNumber :"$phoneNumber" }}}}
        ]).toArray(function (err, building) {
            //res.send({building:building,result:result}); 
            // or
            res.send(JSON.stringify{building:building,result:result});

    });        
        } catch(err) {
            return res.json({
                         success: false,
                         message: 'error'
    });
        }
    });