Ahmad-w4-database-assignment

Week4/.gitignore

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+.env
+node_modules/

Week4/homework/ex1-aggregation/1-importDataPopulation.js

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+import fs from "fs";
+import csv from "csv-parser";
+import { MongoClient } from "mongodb";
+import dotenv from "dotenv";
+dotenv.config();
+
+const client = new MongoClient(process.env.MONGO_URI);
+
+async function run() {
+try {
+await client.connect();
+console.log("Connected to MongoDB");
+
+const db = client.db("databaseWeek4");
+const collection = db.collection("population");
+
+const results = [];
+
+fs.createReadStream("./homework/ex1-aggregation/population_pyramid_1950-2022.csv")
+    .pipe(csv())
+    .on("data", (row) => {
+    results.push({
+        country: row.Country,
+        year: Number(row.Year),
+        age: row.Age,
+        male: Number(row.M),
+        female: Number(row.F),
+    });
+    })
+    .on("end", async () => {
+    const inserted = await collection.insertMany(results);
+    console.log("Inserted:", inserted.insertedCount, "documents");
+    await client.close();
+    });
+
+} catch (err) {
+console.error(err);
+}
+}
+
+run();

Week4/homework/ex1-aggregation/2-TotalPopulation.js

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+import { MongoClient } from "mongodb";
+import dotenv from "dotenv";
+dotenv.config();
+
+const client = new MongoClient(process.env.MONGO_URI);
+
+async function getPopulationByCountry(countryName) {
+try {
+await client.connect();
+const db = client.db("databaseWeek4");
+const collection = db.collection("population");
+
+const result = await collection.aggregate([
+    { $match: { Country: countryName } },
+    { 
+    $group: { 
+        _id: "$Year", 
+        countPopulation: { $sum: { $add: ["$M", "$F"] } } 
+    } 
+    },
+    { $sort: { _id: 1 } }
+]).toArray();
+
+return result;
+
+} catch (err) {
+console.error(err);
+} finally {
+await client.close();
+}
+}
+
+// Example usage:
+getPopulationByCountry("Netherlands").then(res => console.log(res));

Week4/homework/ex1-aggregation/3-AllTheInformation.js

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+import { MongoClient } from "mongodb";
+import dotenv from "dotenv";
+dotenv.config();
+
+const client = new MongoClient(process.env.MONGO_URI);
+
+
+async function getContinentPopulationByYearAndAge(year, age) {
+try {
+await client.connect();
+const db = client.db("databaseWeek4");
+const collection = db.collection("population");
+
+const result = await collection.aggregate([
+    { $match: { Year: year, Age: age } },
+    { $addFields: { TotalPopulation: { $add: ["$M", "$F"] } } },
+    { $sort: { Country: 1 } }
+]).toArray();
+
+return result;
+
+} catch (err) {
+console.error("Error:", err);
+} finally {
+await client.close();
+}
+}
+
+// Example usage:
+getContinentPopulationByYearAndAge(2020, "100+").then(res => console.log(res));

Week4/homework/ex2-transaction/index.js

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+import { setup } from "./setup.js";
+import { transferAmount } from "./transfer.js";
+
+async function main() {
+await setup();
+await transferAmount(101, 102, 1000);
+}
+
+main();

Week4/homework/ex2-transaction/package.json

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+{
+  "name": "ex2-transaction",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "type": "module",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "dotenv": "^17.2.3",
+    "mongodb": "^7.0.0"
+  }
+}

Week4/homework/ex2-transaction/setup.js

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+import { MongoClient } from "mongodb";
+import dotenv from "dotenv";
+dotenv.config();
+
+const client = new MongoClient(process.env.MONGO_URI);
+
+export async function setup() {
+try {
+await client.connect();
+const db = client.db("databaseWeek4");
+const accounts = db.collection("accounts");
+const accountChanges = db.collection("account_changes");
+
+// Clear previous data
+await accounts.deleteMany({});
+
+await accountChanges.deleteMany({});
+
+// Insert sample accounts
+await accounts.insertMany([
+    { account_number: 101, balance: 5000, account_changes: [] },
+    { account_number: 102, balance: 3000, account_changes: [] }
+]);
+
+console.log("Setup done: accounts created with account_changes array.");
+} catch (err) {
+console.error(err);
+} finally {
+await client.close();
+}
+}
+