Elias Week 4 database

Week1/assignment/meetup.js

@@ -0,0 +1,102 @@
+// Import the mysql package
+const mysql = require('mysql2/promise');
+
+// Create a connection to the database
+async function main() {
+    const connection = await mysql.createConnection({
+        host: 'localhost',  
+        user: 'hyfuser', 
+        password: 'hyfpassword',
+    });
+
+    try {
+        console.log('Connected as id ' + connection.threadId);
+
+        await connection.query('DROP DATABASE IF EXISTS meetup');
+        console.log('Database dropped.');
+
+        await connection.query('CREATE DATABASE meetup');
+        console.log('Database created.');
+
+        // Use the newly created database
+        await connection.query('USE meetup');
+
+        // Create Invitee table
+        const createInviteeTable = `
+            CREATE TABLE Invitee (
+                invitee_no INT AUTO_INCREMENT PRIMARY KEY,
+                invitee_name VARCHAR(255) NOT NULL,
+                invited_by INT,
+                FOREIGN KEY (invited_by) REFERENCES Invitee(invitee_no)
+            )`;
+        await connection.query(createInviteeTable);
+        console.log('Invitee table created.');
+
+        // Create Room table
+        const createRoomTable = `
+            CREATE TABLE Room (
+                room_no INT AUTO_INCREMENT PRIMARY KEY,
+                room_name VARCHAR(255) NOT NULL,
+                floor_number TINYINT NOT NULL
+            )`;
+        await connection.query(createRoomTable);
+        console.log('Room table created.');
+
+        // Create Meeting table
+        const createMeetingTable = `
+            CREATE TABLE Meeting (
+                meeting_no INT AUTO_INCREMENT PRIMARY KEY,
+                meeting_title VARCHAR(255) NOT NULL,
+                starting_time DATETIME NOT NULL,
+                ending_time DATETIME NOT NULL,
+                room_no INT,
+                FOREIGN KEY (room_no) REFERENCES Room(room_no)
+            )`;
+        await connection.query(createMeetingTable);
+        console.log('Meeting table created.');
+
+        // Insert data into Invitee table
+        const insertInvitee = `
+            INSERT INTO Invitee (invitee_name, invited_by)
+            VALUES 
+                ('John Doe', NULL),  -- Assuming initial invitees are not invited by anyone
+                ('Jane Doe', NULL),
+                ('Alice Smith', NULL),
+                ('Bob Johnson', NULL),
+                ('Charlie Brown', NULL)`;
+        await connection.query(insertInvitee);
+        console.log('5 rows inserted into Invitee table.');
+
+        // Insert data into Room table
+        const insertRoom = `
+            INSERT INTO Room (room_name, floor_number)
+            VALUES 
+                ('Conference Room A', 1),
+                ('Conference Room B', 1),
+                ('Meeting Room C', 2),
+                ('Board Room', 3),
+                ('Lounge', 1)`;
+        await connection.query(insertRoom);
+        console.log('5 rows inserted into Room table.');
+
+        // Insert data into Meeting table
+        const insertMeeting = `
+            INSERT INTO Meeting (meeting_title, starting_time, ending_time, room_no)
+            VALUES 
+                ('Project Kickoff', '2024-10-15 09:00:00', '2024-10-15 10:00:00', 1),
+                ('Weekly Sync', '2024-10-15 10:30:00', '2024-10-15 11:30:00', 2),
+                ('Client Meeting', '2024-10-15 14:00:00', '2024-10-15 15:00:00', 3),
+                ('Team Building', '2024-10-15 16:00:00', '2024-10-15 17:00:00', 4),
+                ('Product Review', '2024-10-15 11:00:00', '2024-10-15 12:00:00', 5)`;
+        await connection.query(insertMeeting);
+        console.log('5 rows inserted into Meeting table.');
+
+    } catch (err) {
+        console.error('Error: ', err);
+    } finally {
+        // End the connection
+        await connection.end();
+    }
+}
+
+main();

Week1/assignment/queries.js

@@ -0,0 +1,70 @@
+const mysql = require('mysql2');
+
+// Create a connection to the database
+const connection = mysql.createConnection({
+  host: 'localhost', 
+  user: 'hyfuser', 
+  password: 'hyfpassword', 
+  database: 'world' 
+});
+
+// Connect to the database
+connection.connect((err) => {
+  if (err) {
+    console.error('Error connecting to the database:', err.stack);
+    return;
+  }
+  console.log('Connected to the database.');
+});
+
+const queries = [
+  // 1. Countries with population greater than 8 million
+  `SELECT Name FROM country WHERE Population > 8000000`,
+
+  // 2. Countries that have "land" in their names
+  `SELECT Name FROM country WHERE Name LIKE '%land%'`,
+
+  // 3. Cities with population between 500,000 and 1 million
+  `SELECT Name FROM city WHERE Population BETWEEN 500000 AND 1000000`,
+
+  // 4. All countries in Europe
+  `SELECT Name FROM country WHERE Continent = 'Europe'`,
+
+  // 5. Countries in descending order of surface area
+  `SELECT Name FROM country ORDER BY SurfaceArea DESC`,
+
+  // 6. All cities in the Netherlands
+  `SELECT Name FROM city WHERE CountryCode = 'NLD'`,
+
+  // 7. Population of Rotterdam
+  `SELECT Population FROM city WHERE Name = 'Rotterdam'`,
+
+  // 8. Top 10 countries by surface area
+  `SELECT Name FROM country ORDER BY SurfaceArea DESC LIMIT 10`,
+
+  // 9. Top 10 most populated cities
+  `SELECT Name FROM city ORDER BY Population DESC LIMIT 10`,
+
+  // 10. Population number of the world
+  `SELECT SUM(Population) AS WorldPopulation FROM country`
+];
+
+// Execute all queries and log results
+queries.forEach((query, index) => {
+  connection.query(query, (error, results) => {
+    if (error) {
+      console.error(`Error executing query ${index + 1}:`, error);
+    } else {
+      console.log(`Results of query ${index + 1}:`, results);
+    }
+  });
+});
+
+// Close the connection
+connection.end((err) => {
+  if (err) {
+    console.error('Error closing the connection:', err);
+  } else {
+    console.log('Connection closed.');
+  }
+});

Week2/assignment/aggregate.js

@@ -0,0 +1,62 @@
+const mysql = require('mysql2');
+
+// Create a connection to the database
+const connection = mysql.createConnection({
+    host: 'localhost',
+    user: 'hyfuser',
+    password: 'hyfpassword',
+    database: 'userdb'
+});
+
+// Query for all research papers and the number of authors that wrote each paper
+const queryPapersAndAuthorsCount = `
+SELECT rp.paper_title, COUNT(ap.author_id) AS number_of_authors
+FROM research_papers rp
+LEFT JOIN author_paper ap ON rp.paper_id = ap.paper_id
+GROUP BY rp.paper_id;`;
+
+// Query for sum of research papers published by all female authors
+const queryFemalePapersCount = `
+SELECT COUNT(DISTINCT rp.paper_id) AS total_female_papers
+FROM research_papers rp
+JOIN author_paper ap ON rp.paper_id = ap.paper_id
+JOIN authors a ON ap.author_id = a.author_id
+WHERE a.gender = 'Female';`;
+
+// Query for average h-index of all authors per university
+const queryAverageHIndex = `
+SELECT university, AVG(h_index) AS average_h_index
+FROM authors
+GROUP BY university;`;
+
+// Query for sum of research papers of authors per university
+const queryTotalPapersPerUniversity = `
+SELECT a.university, COUNT(DISTINCT rp.paper_id) AS total_papers
+FROM authors a
+JOIN author_paper ap ON a.author_id = ap.author_id
+JOIN research_papers rp ON ap.paper_id = rp.paper_id
+GROUP BY a.university;`;
+
+// Query for minimum and maximum of h-index of all authors per university
+const queryMinMaxHIndex = `
+SELECT university, MIN(h_index) AS min_h_index, MAX(h_index) AS max_h_index
+FROM authors
+GROUP BY university;`;
+
+// Function to execute a query and log the result
+function executeQuery(query, logMessage) {
+    connection.query(query, (error, results) => {
+        if (error) throw error;
+        console.log(logMessage, results);
+    });
+}
+
+// Execute the queries
+executeQuery(queryPapersAndAuthorsCount, 'Research papers and number of authors:');
+executeQuery(queryFemalePapersCount, 'Total research papers by female authors:');
+executeQuery(queryAverageHIndex, 'Average H-index per university:');
+executeQuery(queryTotalPapersPerUniversity, 'Total research papers per university:');
+executeQuery(queryMinMaxHIndex, 'Min and Max H-index per university:');
+
+// Close the connection
+connection.end();

Week2/assignment/authors.js

@@ -0,0 +1,34 @@
+const mysql = require('mysql2');
+
+// Create a connection to the database
+const connection = mysql.createConnection({
+    host: 'localhost',
+    user: 'hyfuser',
+    password: 'hyfpassword',
+    database: 'userdb'
+});
+
+// SQL command to create the authors table
+const createAuthorsTable = `
+CREATE TABLE authors (
+    author_id INT AUTO_INCREMENT PRIMARY KEY,
+    author_name VARCHAR(255) NOT NULL,
+    university VARCHAR(255),
+    date_of_birth DATE,
+    h_index INT,
+    gender ENUM('Male', 'Female', 'Other'),
+    mentor INT,
+    FOREIGN KEY (mentor) REFERENCES authors(author_id)
+);`;
+
+// Execute the SQL command
+connection.query(createAuthorsTable, (error, results) => {
+    if (error) {
+        console.error('Error creating table:', error);
+        return;
+    }
+    console.log('Authors table created successfully.');
+});
+
+// Close the connection
+connection.end();

Week2/assignment/createAuthorPaperTable.js

@@ -0,0 +1,27 @@
+const mysql = require('mysql2');
+
+const connection = mysql.createConnection({
+    host: 'localhost',
+    user: 'hyfuser',
+    password: 'hyfpassword',
+    database: 'userdb'
+});
+
+const createAuthorPaperTable = `
+CREATE TABLE author_paper (
+    author_id INT,
+    paper_id INT,
+    FOREIGN KEY (author_id) REFERENCES authors(author_id),
+    FOREIGN KEY (paper_id) REFERENCES research_papers(paper_id),
+    PRIMARY KEY (author_id, paper_id)
+);`;
+
+connection.query(createAuthorPaperTable, (error, results) => {
+    if (error) {
+        console.error('Error creating author_paper table:', error);
+        return;
+    }
+    console.log('Author-paper association table created successfully.');
+});
+
+connection.end();

Week2/assignment/createResearchPapersTable.js

@@ -0,0 +1,28 @@
+const mysql = require('mysql2');
+
+// Create a connection to the database
+const connection = mysql.createConnection({
+    host: 'localhost',
+    user: 'hyfuser',
+    password: 'hyfpassword',
+    database: 'userdb'
+});
+
+const createResearchPapersTable = `
+CREATE TABLE research_papers (
+    paper_id INT AUTO_INCREMENT PRIMARY KEY,
+    paper_title VARCHAR(255) NOT NULL,
+    conference VARCHAR(255),
+    publish_date DATE
+);`;
+
+connection.query(createResearchPapersTable, (error, results) => {
+    if (error) {
+        console.error('Error creating research_papers table:', error);
+        return;
+    }
+    console.log('Research papers table created successfully.');
+});
+
+// Close the connection
+connection.end();