DEV Community: Lakshya Tyagi

Resolve Routing issue on Server

Lakshya Tyagi — Fri, 10 Nov 2023 09:27:13 +0000

So i was facing Routing issue after deploying my React JS build on server. On local system my routing was working fine but after deploying over the server it wasn't routing on next pages.

Error Was

## Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator at webmaster@localhost to inform them of the time this error occured, and the actions you performed just before this error.
More information about this error may be available in the server log.

---
Apache/2.4.52 (Ubuntu) Server at XX.XXX.X.XXX Port XXXX

After trying alot i have tried to create a .htaccess file in build folder

content you can add in .htaccess file

<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteBase /
    RewriteRule ^index\.html$ - [L]
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule . /index.html [L]
</IfModule>

Stuck in SQL query

Lakshya Tyagi — Thu, 08 Sep 2022 19:29:07 +0000

Hello Everyone, Let's start this series with a SQL Makeshifter (Jugaad). So, today I got stuck in a SQL query. Let's understand the problem statement and solution I did.

Problem Statement

I have a table where I have id (Primary Key), Date Entered, Name of person, Person Id, Score, Score Type

There can be multiple entries of same Person having same Score Type. We need single details of each person with each score type having maximum Date Entered.

Let's have a sample table

Table Name: Student
| id | Date Entered | Name of Person | Person Id | Score | Score Type |
-----------------------------------------------------------------------
| 1 | 2022-08-27 | Mark | 101 | 6 | AA |
| 2 | 2022-07-08 | Alex | 102 | 3 | AA |
| 3 | 2022-08-29 | Mark | 101 | 9 | AB |
| 4 | 2022-09-01 | Mark | 101 | 2 | AA |
| 5 | 2022-02-12 | Alex | 102 | 5 | AB |
| 6 | 2022-09-09 | Alex | 102 | 9 | AB |
----------------------------------------

Expected Output

| id | Date Entered | Name of Person | Person Id | Score | Score Type |
-----------------------------------------------------------------------
| 4 | 2022-09-01 | Mark | 101 | 2 | AA |
| 3 | 2022-08-29 | Mark | 101 | 9 | AB |
| 2 | 2022-07-08 | Alex | 102 | 3 | AA |
| 6 | 2022-09-09 | Alex | 102 | 9 | AB |
----------------------------------------

1st attempt to get this output

We have thought to use group by using having clause and we made this query.

SELECT * FROM student s GROUP BY Person Id, Score Type HAVING MAX(Date Entered);

We got wrong output using this query. We are not getting result having latest Date Entered.

2nd attempt to get this output

After spending time on google I have seen that everyone is using condition in HAVING clause, so I have tried this now

SELECT * FROM student s GROUP BY Person Id, Score Type HAVING Date Entered = MAX(Date Entered);

Again this didn't work

3rd attempt with successful result

After getting failed in 2nd attempt I tried it myself and tried to make a mapping in my mind and I have tried a sub query concept this time.

SELECT * FROM (SELECT * FROM student s GROUP BY Person Id, Score Type, Date Entered ORDER BY Date Entered desc) latest_student GROUP BY Person Id, Score Type;

Here I got my expected output

So this is what I have tried today with SQL. Now it's your turn to tell any other possible way to write a query having same expected result.

Do let me know your views on it in comment.

Decision of New Series

Lakshya Tyagi — Wed, 07 Sep 2022 12:27:45 +0000

Hello Everyone, After a long time I am back on this platform again and this time I have decided to start a New Series Tech Challenges Stories.

Why I am starting this series?
On the daily basis I face new challenges while coding and that I solve using some tricks or Jugaad . That's what I want to share and discuss with everyone. What kind of tricks I am using to solve those problems or their can be a better solution of that problem which we can get to know from each other. I hope you all will help me in providing a better solution.

What kind of problems I cover in this series?

Problems related to coding.
Problems related to DevOps.
Problems related to Leadership and Management
Problems related to Architecture. In initial phase we will start more from coding and DevOps.

If you want me to cover any other topics too then do let me know in comment box.

Only Numbers validation in JS

Lakshya Tyagi — Sun, 27 Feb 2022 04:30:12 +0000

public numberOnlyValidation(event: any) {
    const pattern = /[0-9]/;
    let inputChar = String.fromCharCode(event.charCode);
    if (!pattern.test(inputChar)) {
        event.preventDefault();
    }
}

Validate Phone Number

Lakshya Tyagi — Mon, 14 Feb 2022 17:55:27 +0000

validatePhoneNo(num) {
    var phonenum = /^\d{10}$/;
    var str = num;
    if((str.match(phonenum))) {
        return true;
    } else {
        return false;
    }
}

Javascript function to check is object empty or not

Lakshya Tyagi — Mon, 31 Jan 2022 17:14:53 +0000

function isObjectEmpty(obj) {
    for (var key in obj) {
        if (obj.hasOwnProperty(key))
            return false;
    }
    return true;
}

C++ Projects you should try

Lakshya Tyagi — Mon, 08 Feb 2021 10:02:18 +0000

Beginners:

Calculator
Currency Convertor
Tic Tac Toe

Intermediate:

Management System
Billing System
ATM Interface

Advanced:

Browser
Compiler
Database

Add more in the comment

JavaScript Code Daily Challenge #14

Lakshya Tyagi — Mon, 14 Dec 2020 03:02:04 +0000

About

This is a series of JavaScript Code Daily Challenge. Each day I show a few solutions written in JavaScript. The questions are from coding practice/contest sites such as HackerRank, LeetCode, Codeforces, Atcoder and etc.

Circular Array Rotation
https://www.hackerrank.com/challenges/circular-array-rotation/problem

'use strict';

const fs = require('fs');

process.stdin.resume();
process.stdin.setEncoding('utf-8');

let inputString = '';
let currentLine = 0;

process.stdin.on('data', inputStdin => {
    inputString += inputStdin;
});

process.stdin.on('end', function() {
    inputString = inputString.replace(/\s*$/, '')
        .split('\n')
        .map(str => str.replace(/\s*$/, ''));

    main();
});

function readLine() {
    return inputString[currentLine++];
}

Complete the circular ArrayRotation function in the comment

function circularArrayRotation(a, k, queries) {


}


javascript
function main() {
    const ws = fs.createWriteStream(process.env.OUTPUT_PATH);

    const nkq = readLine().split(' ');

    const n = parseInt(nkq[0], 10);

    const k = parseInt(nkq[1], 10);

    const q = parseInt(nkq[2], 10);

    const a = readLine().split(' ').map(aTemp => parseInt(aTemp, 10));

    let queries = [];

    for (let i = 0; i < q; i++) {
        const queriesItem = parseInt(readLine(), 10);
        queries.push(queriesItem);
    }

    const result = circularArrayRotation(a, k, queries);

    ws.write(result.join('\n') + '\n');

    ws.end();
}

Which among them is used to create an object?

Lakshya Tyagi — Sun, 13 Dec 2020 16:48:53 +0000

Write your answer in comment

1. A class
2. A function
3. A method
4. A constructor

JavaScript Code Daily Challenge #13

Lakshya Tyagi — Sat, 12 Dec 2020 11:44:27 +0000

About

Find Digits
https://www.hackerrank.com/challenges/find-digits/problem

'use strict';

const fs = require('fs');

process.stdin.resume();
process.stdin.setEncoding('utf-8');

let inputString = '';
let currentLine = 0;

process.stdin.on('data', inputStdin => {
    inputString += inputStdin;
});

process.stdin.on('end', _ => {
    inputString = inputString.replace(/\s*$/, '')
        .split('\n')
        .map(str => str.replace(/\s*$/, ''));

    main();
});

function readLine() {
    return inputString[currentLine++];
}

Complete the function findDigits(n) in comment

function findDigits(n) {


}

function main() {
    const ws = fs.createWriteStream(process.env.OUTPUT_PATH);

    const t = parseInt(readLine(), 10);

    for (let tItr = 0; tItr < t; tItr++) {
        const n = parseInt(readLine(), 10);

        let result = findDigits(n);

        ws.write(result + "\n");
    }

    ws.end();
}

What will be the Output of given python code?

Lakshya Tyagi — Sat, 12 Dec 2020 10:48:59 +0000

y = 8
z = lambda x:x*y
print z(6)

Write your answer in comment with explaination

What will be the output of given python code?

Lakshya Tyagi — Tue, 08 Dec 2020 08:44:28 +0000

a, b = 12, 5
if a+b:
    print('True')
else:
    print('False')

Write output with explanation in comment