Added Class constructor

lib/Class.js

@@ -1,10 +1,57 @@
 'use strict';
 
+const DatabaseConnectionPool = require('./DatabaseConnectionPool');
+
 class Class {
-	classId;
+	/**
+	 * The id of the class
+	 * @type {string}
+	 */
+	id;
+
+	/**
+	 * The id of the subject the class is for
+	 * @type {string}
+	 */
 	subjectId;
+
+	/**
+	 * The name of the class
+	 * @type {string}
+	 */
 	name;
 
+	/**
+	 * @param {string} classID - The id of the class to fetch
+	 */
+	constructor(classId) {
+		const sql = `
+			select
+				classId as id,
+				name,
+				subjectId
+			from
+				class
+			where
+				classId = ?;
+		`;
+
+		return (async () => {
+			const conn = await new DatabaseConnectionPool();
+			const record = await conn.runQuery(sql, [
+				classId,
+			]);
+
+			if (!record.length)
+				throw new Error('No class found');
+
+			for (const [ k, v ] of Object.entries(record[0]))
+				this[k] = v;
+
+			return this;
+		})();
+	}
+
 	get subject() {
 
 	}