Using a framework of your choice, write a program that does basic CRUD operation using a DBMS of your choice while adhering to best coding practices

A simple CRUD made with Reactjs, Nodejs and Mysql

• Reactjs
• Nodejs
• Mysql

To install and run the

1. Frontend - Download the zip file, navigate to the client folder then run the commands below
   npm install
npm run dev

2. Backend - Download the zip file, navigate to the server folder then run the commands below
   npm install
npm run dev

Write a simple , well documented source code that reads from a text file, searches for a specific string and displays the number of occurrences of that string in the text file.

This JavaScript file contains two main functions: readFile and countOccurrences.

The readFile function takes a file path as an argument and reads the file content synchronously using Node.js's fs.readFileSync method. The content of the file is returned as a string.

function readFile(filePath) {
    return fs.readFileSync(filePath, 'utf8');
}

The countOccurrences function takes two arguments: a text to search in and a string to search for. It creates a global regular expression with the search string and uses the match method to find all occurrences of the search string in the text. The number of matches is returned.

function countOccurrences(text, searchString) {
    const regex = new RegExp(searchString, 'g');
    return (text.match(regex) || []).length;
}

The script reads a text file (sampleFile.txt) and counts the number of occurrences of the string 'amet' in the file content.

const text = readFile('Question 4/sampleFile.txt');
const occurrences = countOccurrences(text, 'amet');
console.log(occurrences);

The result is logged to the console.

Write a function that reads any of the following file formats, removes special characters and converts the file to an sql file with headers

This JavaScript file contains three main functions: removeSpecialCharacters, convertToSql, and writeSqlFile.

The removeSpecialCharacters function takes a string as an argument and removes any special characters from it, leaving only alphanumeric characters and spaces.

function removeSpecialCharacters(str) {
    return str.replace(/[^a-zA-Z0-9 ]/g, "");
}

The convertToSql function takes an input file path and an output path as arguments. It determines the file extension of the input file and reads the file accordingly. If the file is a CSV file, it uses the csv-parser module to parse the file. If the file is an XLSX file, it uses the xlsx module. The function removes any special characters from the data and stores the cleaned data in an array.

function convertToSql(inputPath, outputPath) {
    // ...
}

The writeSqlFile function takes the cleaned data and an output path as arguments. It generates a string that represents the SQL commands to create a table and insert the data into the table. This string is then written to a new .sql file at the output path.

function writeSqlFile(data, outputPath) {
    // ...
}

The script can be used to convert a CSV or XLSX file to an SQL file with the data cleaned of special characters. The input file path and output path should be provided as arguments to the convertToSql function.

convertToSql('path/to/input.csv', 'path/to/output.sql');

The output will be an SQL file with commands to create a table and insert the cleaned data.

Using the language of your choice develop a solution that provided url can be able to shorten the url with a custom domain name

This JavaScript file contains two main functions: shortenUrl and getOriginalUrl, and a urlDatabase object to store the original URLs.

The shortenUrl function takes two arguments: the original URL and a custom domain. It generates a random 8-character hexadecimal string using Node.js's crypto.randomBytes method. This string is used as a short ID for the original URL, which is stored in the urlDatabase object. The function then returns the short URL, which is the custom domain followed by the short ID.

function shortenUrl(originalUrl, customDomain) {
    const shortId = crypto.randomBytes(4).toString('hex');
    urlDatabase[shortId] = originalUrl;
    return `${customDomain}/${shortId}`;
}

The getOriginalUrl function takes a short ID as an argument and returns the original URL from the urlDatabase object.

function getOriginalUrl(shortId) {
    return urlDatabase[shortId];
}

The script first shortens a URL ('https://www.example.com') using a custom domain ('http://mydomain') and logs the short URL to the console. It then extracts the short ID from the short URL, retrieves the original URL using the short ID, and logs the original URL to the console.

const shortUrl = shortenUrl('https://www.example.com', 'http://mydomain');
console.log(shortUrl);

const shortId = shortUrl.split('/').pop();

const originalUrl = getOriginalUrl(shortId);
console.log(originalUrl);

The output should be the short URL followed by the original URL.