Rizan ibrahim w2 database

Week2/assignment/Aggregate_Functions.js

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+import mysql from "mysql2/promise";
+
+const connection = await mysql.createConnection({
+  host: "localhost",
+  user: "hyfuser",
+  password: "hyfpassword",
+  database: "database_assingnment",
+});
+console.log(" Connected to database: database_assingnment");
+
+const [paperAuthors] = await connection.execute(`
+  select 
+    rp.paper_id,
+    rp.paper_title,
+    count(ap.author_id) as number_of_authors
+  from research_Papers rp
+  join author_paper ap on rp.paper_id = ap.paper_id
+  group by rp.paper_id, rp.paper_title
+`);
+console.log("all research papers and number of authors that wrote them");
+console.table(paperAuthors);
+
+//
+const [femalePaperCount] = await connection.execute(`
+  select count(distinct ap.paper_id) as total_unique_female_papers
+  from author_paper ap
+  join authors a ON ap.author_id = a.author_id
+  where a.gender = 'female'
+  `);
+console.log("total research papers by femal authors");
+console.table(femalePaperCount);
+
+//
+const [avgHIndexPerUni] = await connection.execute(`
+  select university, avg(h_index) as average_h_index
+  from authors
+  group by university
+`);
+console.log("Average h-index per university");
+console.table(avgHIndexPerUni);
+
+//
+const [totalPapersPerUni] = await connection.execute(`
+  select a.university, count(distinct ap.paper_id) as total_unique_papers
+  from authors a
+  join author_paper ap ON a.author_id = ap.author_id
+  group by a.university
+`);
+console.log("Total research papers per university");
+console.table(totalPapersPerUni);
+
+//
+const [minMaxHIndex] = await connection.execute(`
+  select university, min(h_index) as min_h_index, max(h_index) as max_h_index
+  from authors
+  group by university
+`);
+console.log("min and max h-index per university:");
+console.table(minMaxHIndex);
+
+//
+await connection.end();

Week2/assignment/joins.js

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+import mysql from "mysql2/promise";
+
+const connection = await mysql.createConnection({
+  host: "localhost",
+  user: "hyfuser",
+  password: "hyfpassword",
+  database: "database_assingnment",
+});
+console.log(" Connected to database: database_assingnment");
+
+const [authorsWithMentors] = await connection.execute(`
+  select a.author_name as author,
+  m.author_name as mentor
+  from authors a left join authors m on a.mentor = m.author_id
+
+  `);
+console.log("authors and thier mentors");
+console.table(authorsWithMentors);
+
+//
+
+const [authorsAndPapers] = await connection.execute(`
+  select a.author_name as author,
+  rp.paper_title as paper from authors a 
+  left join author_paper ap on a.author_id = ap.author_id 
+  left join research_papers rp ON ap.paper_id = rp.paper_id
+
+  `);
+
+console.log("Authors and their papers:");
+console.table(authorsAndPapers);
+//
+
+await connection.end();

Week2/assignment/keys.js

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+import mysql from "mysql2/promise";
+
+const connection = await mysql.createConnection({
+  host: "localhost",
+  user: "hyfuser",
+  password: "hyfpassword",
+  database: "database_assingnment",
+});
+console.log(" Connected to database: database_assingnment");
+//
+await connection.execute(`DROP TABLE IF EXISTS author_paper`);
+await connection.execute(`DROP TABLE IF EXISTS research_papers`);
+await connection.execute(`DROP TABLE IF EXISTS authors`);
+
+await connection.execute(`
+   create table authors (
+    author_id INT auto_increment primary key,
+    author_name varchar(100),
+    university varchar(100),
+    date_of_birth date,
+    h_index INT,
+    gender varchar(10),
+    mentor INT,
+    foreign key (mentor) REFERENCES authors(author_id)
+  );
+
+  `);
+
+console.log('Table "authors" created with mentor as foreign key');
+
+//
+await connection.execute(`
+  insert into authors (author_name, university, date_of_birth, h_index, gender)
+  values 
+    ('rizan', 'hyf', '1998-01-01', 45, 'male'),
+    ('gea', 'Stanford', '1975-05-15', 38, 'female'),
+    ('araz', 'Oxford', '1992-11-23', 29, 'male');
+`);
+
+await connection.end();

Week2/assignment/package.json

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+{
+  "name": "assignment",
+  "version": "1.0.0",
+  "main": "Aggregate_Functions.js",
+  "type": "module",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "description": "",
+  "dependencies": {
+    "mysql2": "^3.14.1"
+  }
+}

Week2/assignment/relationships.js

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+import mysql from "mysql2/promise";
+
+const connection = await mysql.createConnection({
+  host: "localhost",
+  user: "hyfuser",
+  password: "hyfpassword",
+  database: "database_assingnment",
+});
+console.log(" Connected to database: database_assingnment");
+
+await connection.execute(`drop table if exists author_paper`);
+await connection.execute(`drop table if exists research_papers`);
+
+/// Clean up data and reset auto-increment
+
+await connection.execute(`ALTER TABLE authors AUTO_INCREMENT = 1`);
+
+await connection.execute(`
+    create table research_papers(
+    paper_id int auto_increment primary key,
+    paper_title varchar(100),
+    conference varchar(100),
+    publish_date date
+
+  )
+  `);
+console.log("Table 'research_papers' created");
+
+await connection.execute(`
+  create table author_paper (
+    author_id INT,
+    paper_id INT,
+    primary key (author_id, paper_id),
+    foreign key (author_id) references authors(author_id) on delete CASCADE,
+    foreign key (paper_id) references research_papers(paper_id) on delete CASCADE
+  );
+`);
+console.log("Table 'author_paper'junction table created");
+
+await connection.execute(`
+  insert into  research_papers (paper_title, conference, publish_date)
+  values 
+    ('AI in Healthcare', 'NeurIPS', '2022-12-01'),
+    ('Quantum Computing Basics', 'QCon', '2023-06-15'),
+    ('Climate Change Models', 'UNConf', '2021-09-20');
+`);
+
+console.log("Sample research papers inserted");
+
+//
+await connection.execute(`
+  insert  into author_paper (author_id, paper_id)
+  values
+    (1, 1),
+    (1, 2),
+    (2, 2),
+    (3, 3);
+`);
+console.log("Sample author-paper relationships inserted");
+
+await connection.end();