asynch

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function

mongodb query

https://www.w3resource.com/mongodb/mongodb-logical-and-not-operators.php



filter date in array then link table group the id and push element in object


db.listing_links.aggregate([
    {
        $project: {
            "views": {
                $filter: {
                    input: '$views',
                    as: 'item',
                    cond: { $and: [{ $gt: ['$$item.viewed_on', ISODate("2019-09-22T00:39:31.280+05:30")] }, { $lte: ['$$item.viewed_on', ISODate("2019-09-25T00:39:31.280+05:30")] }] }
                }
            },
            "listing_id": "$listing_id",
            "creator_id": "$creator_id",
            "listing_owner_id": "$listing_owner_id",
            "last_accessed": "$last_accessed"
        }
    },
    {
        $lookup: {
            from: "users",
            localField: "creator_id",
            foreignField: "_id",
            'as': "user_types"
        }
    },
    {
        $group: {
            _id: "$creator_id",
            filteredData: {
                $push: {"user_types":"$user_types","views":"$views"}
            },
        }
    }
])db.listing_links.aggregate([
    {
        $project: {
            "views": {
                $filter: {
                    input: '$views',
                    as: 'item',
                    cond: { $and: [{ $gt: ['$$item.viewed_on', ISODate("2019-09-22T00:39:31.280+05:30")] }, { $lte: ['$$item.viewed_on', ISODate("2019-09-25T00:39:31.280+05:30")] }] }
                }
            },
            "listing_id": "$listing_id",
            "creator_id": "$creator_id",
            "listing_owner_id": "$listing_owner_id",
            "last_accessed": "$last_accessed"
        }
    },
    {
        $lookup: {
            from: "users",
            localField: "creator_id",
            foreignField: "_id",
            'as': "user_types"
        }
    },
    {
        $group: {
            _id: "$creator_id",
            filteredData: {
                $push: {"user_types":"$user_types","views":"$views"}
            },
        }
    }
])

caseinsencitve search in mongodb

https://stackoverflow.com/questions/7101703/how-do-i-make-case-insensitive-queries-on-mongodb/7101868

db.collection.find( {"name_lower":
    { $regex: new RegExp("^" + thename.toLowerCase(), "i") } }
);

db.collection.find( {"name_lower":
    { $regex: new RegExp("^" + thename.toLowerCase(), "i") } }
);

case insencetive search

https://stackoverflow.com/questions/23028008/meteor-how-to-do-a-case-insensitive-collection-findone

update multipale documents in mongo

https://medium.com/@salonimalhotra1ind/update-multiple-documents-in-mongoose-ea37c04a154f

how to set node envirment variable in windows

go to you node project root directory

then
fire command

$env:q_bingMapKey="Ajf0E"
$env:q_jwtPrivateKey="my"
$env:q_awsPoolId="us-east-1:3313"

difference between let and var

In script you can declare a variable with multiple time.

for example 

var a=20;

var a=30;

console.log(a); //30

but with let you cant redeclare a same variable name.

exp

let data=20;

let data=30;

console.log(data);

//you will get error.

Identifier 'a' has already been declared.

With let you can reassign variable 

like 

let data=20;

data=40;

lombok getter and setter

public class @Data YourClass {

    private int myVar;

}

https://dzone.com/articles/gettersetterthe-most-hated-practice-in-java

https://projectlombok.org/

lambda function exampe

https://stackify.com/aws-lambda-with-node-js-a-complete-getting-started-guide/

serverless response format

https://aws.amazon.com/premiumsupport/knowledge-center/malformed-502-api-gateway/

 var response = {
        "statusCode": 200,
        "headers": {
            "my_header": "my_value"
        },
        "body": JSON.stringify(responseBody),
        "isBase64Encoded": false
    };
    callback(null, response);

serverless command

https://serverless.com/framework/docs/providers/aws/cli-reference/invoke/

timezone conversion

<?php
$game_played_date="2019-02-14 09:59:16";
$to_tz="Europe/Vaduz";
$from_tz="America/New_York";
   $date = new DateTime($game_played_date, new DateTimeZone($from_tz));
   $date->setTimezone(new DateTimeZone($to_tz));                   
   $date_time['current_date'] = $date->format("Y-m-d H:i:s");
   echo $date_time['current_date']."<br>";
 echo date('g:i A', strtotime($date_time['current_date']))."<br>";
echo date('Y-m-d H:i:s', strtotime($date_time['current_date']));
?>