DARYNA-TKACHENKO-WEEK4-DATABASE

Week4/homework/ex1-aggregation/.gitignore

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+.env

Week4/homework/ex1-aggregation/exercise1_population.js

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+require('dotenv').config();
+const { MongoClient } = require('mongodb');
+const fs = require('fs');
+const csv = require('csv-parser');
+
+const DB_NAME = "databaseWeek4";
+const COLLECTION_NAME = "population";
+
+async function importCSV() {
+    const client = new MongoClient(process.env.MONGO_URI);
+    try {
+        await client.connect();
+        const db = client.db(DB_NAME);
+        const collection = db.collection(COLLECTION_NAME);
+
+
+        await collection.deleteMany({});
+        console.log('Collection cleared');
+
+        const results = [];
+
+        return new Promise((resolve, reject) => {
+            fs.createReadStream('population_pyramid_1950-2022.csv')
+                .pipe(csv())
+                .on('data', (data) => {
+
+                    data.M = parseInt(data.M);
+                    data.F = parseInt(data.F);
+                    data.Year = parseInt(data.Year);
+                    results.push(data);
+                })
+                .on('end', async () => {
+                    try {
+                        if (results.length > 0) {
+                            await collection.insertMany(results);
+                            console.log(`Data imported successfully: ${results.length} documents`);
+                        }
+                        await client.close();
+                        resolve();
+                    } catch (err) {
+                        await client.close();
+                        reject(err);
+                    }
+                })
+                .on('error', async (err) => {
+                    await client.close();
+                    reject(err);
+                });
+        });
+    } catch (err) {
+        console.error('Import error:', err);
+        await client.close();
+        throw err;
+    }
+}
+
+async function totalPopulationByCountry(countryName) {
+    const client = new MongoClient(process.env.MONGO_URI);
+    try {
+        await client.connect();
+        const db = client.db(DB_NAME);
+        const collection = db.collection(COLLECTION_NAME);
+
+        const results = await collection.aggregate([
+            { $match: { Country: countryName } },
+            {
+                $group: {
+                    _id: "$Year",
+                    countPopulation: { $sum: { $add: ["$M", "$F"] } }
+                }
+            },
+            { $sort: { _id: 1 } }
+        ]).toArray();
+
+        console.log(`\nTotal population for ${countryName}:`);
+        console.log(JSON.stringify(results, null, 2));
+        return results;
+
+    } catch (err) {
+        console.error('Error in totalPopulationByCountry:', err);
+        return [];
+    } finally {
+        await client.close();
+    }
+}
+
+async function continentPopulation(yearValue, ageValue) {
+    const client = new MongoClient(process.env.MONGO_URI);
+    try {
+        await client.connect();
+        const db = client.db(DB_NAME);
+        const collection = db.collection(COLLECTION_NAME);
+
+        const results = await collection.aggregate([
+            {
+                $match: {
+                    Year: yearValue,
+                    Age: ageValue,
+                    Country: { 
+                        $in: [
+                            "AFRICA",
+                            "ASIA", 
+                            "EUROPE",
+                            "LATIN AMERICA AND THE CARIBBEAN",
+                            "NORTHERN AMERICA",
+                            "OCEANIA"
+                        ] 
+                    }
+                }
+            },
+            {
+                $project: {
+                    Country: 1,
+                    Year: 1,
+                    Age: 1,
+                    M: 1,
+                    F: 1,
+                    TotalPopulation: { $add: ["$M", "$F"] }
+                }
+            }
+        ]).toArray();
+
+        console.log(`\nContinent population for year ${yearValue}, age ${ageValue}:`);
+        console.log(JSON.stringify(results, null, 2));
+        return results;
+
+    } catch (err) {
+        console.error('Error in continentPopulation:', err);
+        return [];
+    } finally {
+        await client.close();
+    }
+}
+
+async function main() {
+    try {
+        // await importCSV();
+        await totalPopulationByCountry("Netherlands");
+        await continentPopulation(2020, "100+");
+
+    } catch (err) {
+        console.error('Main error:', err);
+    }
+}
+
+main();

Week4/homework/ex1-aggregation/exercise2_population.js

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+require('dotenv').config();
+const { MongoClient } = require("mongodb");
+
+const uri = process.env.MONGO_URI;
+const client = new MongoClient(uri);
+
+async function continentPopulation(yearValue, ageValue) {
+    try {
+        await client.connect();
+        const db = client.db("databaseWeek4");
+        const collection = db.collection("population");
+
+        const results = await collection.aggregate([
+            {
+                $match: {
+                    Year: yearValue,
+                    Age: ageValue,
+                    Country: { $in: ["AFRICA", "ASIA", "EUROPE", "LATIN AMERICA AND THE CARIBBEAN", "NORTHERN AMERICA", "OCEANIA"] }
+                }
+            },
+            {
+                $project: {
+                    Country: 1,
+                    Year: 1,
+                    Age: 1,
+                    M: 1,
+                    F: 1,
+                    TotalPopulation: { $add: ["$M", "$F"] }
+                }
+            }
+        ]).toArray();
+
+        console.log(results);
+    } catch (err) {
+        console.error(err);
+    } finally {
+        await client.close();
+    }
+}
+
+continentPopulation(2020, "100+");