Better connection handling

src/models/betterzon/Betterzon.db.ts

@@ -13,7 +13,7 @@ export namespace BetterzonDB {
 		connectionLimit: 5
 	});
 
-    export function getConnection() {
-        return pool;
-    }
+	export const getConnection = async () => {
+		return pool.getConnection();
+	};
 }

src/models/betterzon/categories/categories.service.ts

@@ -18,7 +18,7 @@ dotenv.config();
  * Fetches and returns all known categories
  */
 export const findAll = async (): Promise<Categories> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let categRows = [];
 	try {
 		const rows = await conn.query('SELECT category_id, name FROM categories');
@@ -38,6 +38,9 @@ export const findAll = async (): Promise<Categories> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return categRows;
@@ -48,7 +51,7 @@ export const findAll = async (): Promise<Categories> => {
  * @param id The id of the category to fetch
  */
 export const find = async (id: number): Promise<Category> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let categ: any;
 	try {
 		const rows = await conn.query('SELECT category_id, name FROM categories WHERE category_id = ?', id);
@@ -60,6 +63,9 @@ export const find = async (id: number): Promise<Category> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return categ;
@@ -70,7 +76,7 @@ export const find = async (id: number): Promise<Category> => {
  * @param term the term to match
  */
 export const findBySearchTerm = async (term: string): Promise<Categories> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let categRows = [];
 	try {
 		term = '%' + term + '%';
@@ -83,6 +89,9 @@ export const findBySearchTerm = async (term: string): Promise<Categories> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return categRows;

src/models/betterzon/contact_persons/contact_persons.service.ts

@@ -18,7 +18,7 @@ dotenv.config();
  * Fetches and returns all known contact persons
  */
 export const findAll = async (): Promise<Contact_Persons> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let contRows = [];
 	try {
 		const rows = await conn.query('SELECT contact_person_id, first_name, last_name, gender, email, phone, vendor_id FROM contact_persons');
@@ -30,6 +30,9 @@ export const findAll = async (): Promise<Contact_Persons> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return contRows;
@@ -40,7 +43,7 @@ export const findAll = async (): Promise<Contact_Persons> => {
  * @param id The id of the contact person to fetch
  */
 export const find = async (id: number): Promise<Contact_Person> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let cont: any;
 	try {
 		const rows = await conn.query('SELECT contact_person_id, first_name, last_name, gender, email, phone, vendor_id FROM contact_persons WHERE contact_person_id = ?', id);
@@ -52,6 +55,9 @@ export const find = async (id: number): Promise<Contact_Person> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return cont;
@@ -62,7 +68,7 @@ export const find = async (id: number): Promise<Contact_Person> => {
  * @param id The id of the vendor to fetch contact persons for
  */
 export const findByVendor = async (id: number): Promise<Contact_Persons> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let contRows = [];
 	try {
 		const rows = await conn.query('SELECT contact_person_id, first_name, last_name, gender, email, phone, vendor_id FROM contact_persons WHERE vendor_id = ?', id);
@@ -74,6 +80,9 @@ export const findByVendor = async (id: number): Promise<Contact_Persons> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return contRows;
@@ -90,7 +99,7 @@ export const findByVendor = async (id: number): Promise<Contact_Persons> => {
  * @param phone The phone number of the contact person
  */
 export const createContactEntry = async (user_id: number, vendor_id: number, first_name: string, last_name: string, gender: string, email: string, phone: string): Promise<Boolean> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		// Check if the user is authorized to manage the requested vendor
 		const user_vendor_rows = await conn.query('SELECT vendor_id FROM vendors WHERE vendor_id = ? AND admin_id = ?', [vendor_id, user_id]);
@@ -105,6 +114,9 @@ export const createContactEntry = async (user_id: number, vendor_id: number, fir
 		return res.affectedRows === 1;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -120,7 +132,7 @@ export const createContactEntry = async (user_id: number, vendor_id: number, fir
  * @param phone The phone number of the contact person
  */
 export const updateContactEntry = async (user_id: number, contact_person_id: number, vendor_id: number, first_name: string, last_name: string, gender: string, email: string, phone: string): Promise<Boolean> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		// Check if the user is authorized to manage the requested vendor
 		const user_vendor_rows = await conn.query('SELECT vendor_id FROM vendors WHERE vendor_id = ? AND admin_id = ?', [vendor_id, user_id]);
@@ -135,5 +147,8 @@ export const updateContactEntry = async (user_id: number, contact_person_id: num
 		return res.affectedRows === 1;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/betterzon/crawling_status/crawling_status.service.ts

@@ -17,7 +17,7 @@ dotenv.config();
  * Fetches and returns the current crawling status if the issuing user is an admin
  */
 export const getCurrent = async (): Promise<Crawling_Status> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		// Get the current crawling process
 		let process_info = {
@@ -55,5 +55,8 @@ export const getCurrent = async (): Promise<Crawling_Status> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/betterzon/favorite_shops/favoriteshops.service.ts

@@ -19,13 +19,16 @@ dotenv.config();
  * @param vendor_id The id of the vendor to set as favorite
  */
 export const createFavoriteShop = async (user_id: number, vendor_id: number): Promise<boolean> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		const res = await conn.query('INSERT INTO favorite_shops (vendor_id, user_id) VALUES (?, ?)', [vendor_id, user_id]);
 
 		return res.affectedRows === 1;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -34,7 +37,7 @@ export const createFavoriteShop = async (user_id: number, vendor_id: number): Pr
  * @param user_id
  */
 export const getFavoriteShops = async (user_id: number): Promise<FavoriteShops> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let shops = [];
 	try {
 		const rows = await conn.query('SELECT favorite_id, vendor_id, user_id FROM favorite_shops WHERE user_id = ?', user_id);
@@ -47,6 +50,9 @@ export const getFavoriteShops = async (user_id: number): Promise<FavoriteShops>
 		return shops;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -56,12 +62,15 @@ export const getFavoriteShops = async (user_id: number): Promise<FavoriteShops>
  * @param favorite_id The favorite shop to delete
  */
 export const deleteFavoriteShop = async (user_id: number, favorite_id: number): Promise<boolean> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		const res = await conn.query('DELETE FROM favorite_shops WHERE favorite_id = ? AND user_id = ?', [favorite_id, user_id]);
 
 		return res.affectedRows === 1;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/betterzon/manufacturers/manufacturers.service.ts

@@ -18,7 +18,7 @@ dotenv.config();
  * Fetches and returns all known manufacturers
  */
 export const findAll = async (): Promise<Manufacturers> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let manRows = [];
 	try {
 		const rows = await conn.query('SELECT manufacturer_id, name FROM manufacturers');
@@ -38,6 +38,9 @@ export const findAll = async (): Promise<Manufacturers> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return manRows;
@@ -48,7 +51,7 @@ export const findAll = async (): Promise<Manufacturers> => {
  * @param id The id of the manufacturer to fetch
  */
 export const find = async (id: number): Promise<Manufacturer> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let man: any;
 	try {
 		const rows = await conn.query('SELECT manufacturer_id, name FROM manufacturers WHERE manufacturer_id = ?', id);
@@ -60,6 +63,9 @@ export const find = async (id: number): Promise<Manufacturer> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return man;
@@ -70,7 +76,7 @@ export const find = async (id: number): Promise<Manufacturer> => {
  * @param term the term to match
  */
 export const findBySearchTerm = async (term: string): Promise<Manufacturers> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let manRows = [];
 	try {
 		term = '%' + term + '%';
@@ -83,6 +89,9 @@ export const findBySearchTerm = async (term: string): Promise<Manufacturers> =>
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return manRows;

src/models/betterzon/pricealarms/pricealarms.service.ts

@@ -20,13 +20,16 @@ dotenv.config();
  * @param defined_price The defined price for the price alarm
  */
 export const createPriceAlarm = async (user_id: number, product_id: number, defined_price: number): Promise<boolean> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		const res = await conn.query('INSERT INTO price_alarms (user_id, product_id, defined_price) VALUES (?, ?, ?)', [user_id, product_id, defined_price]);
 
 		return res.affectedRows === 1;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -35,7 +38,7 @@ export const createPriceAlarm = async (user_id: number, product_id: number, defi
  * @param user_id
  */
 export const getPriceAlarms = async (user_id: number): Promise<PriceAlarms> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let priceAlarms = [];
 	try {
 		const rows = await conn.query('SELECT alarm_id, user_id, product_id, defined_price FROM price_alarms WHERE user_id = ?', user_id);
@@ -48,6 +51,9 @@ export const getPriceAlarms = async (user_id: number): Promise<PriceAlarms> => {
 		return priceAlarms;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -58,13 +64,16 @@ export const getPriceAlarms = async (user_id: number): Promise<PriceAlarms> => {
  * @param defined_price The defined price for the price alarm
  */
 export const updatePriceAlarm = async (alarm_id: number, user_id: number, defined_price: number): Promise<boolean> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		const res = await conn.query('UPDATE price_alarms SET defined_price = ? WHERE alarm_id = ? AND user_id = ?', [defined_price, alarm_id, user_id]);
 
 		return res.affectedRows === 1;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -74,12 +83,15 @@ export const updatePriceAlarm = async (alarm_id: number, user_id: number, define
  * @param user_id The id of the user that wants to update the price alarm
  */
 export const deletePriceAlarm = async (alarm_id: number, user_id: number): Promise<boolean> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		const res = await conn.query('DELETE FROM price_alarms WHERE alarm_id = ? AND user_id = ?', [alarm_id, user_id]);
 
 		return res.affectedRows === 1;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/betterzon/prices/prices.service.ts

@@ -18,7 +18,7 @@ dotenv.config();
  * Fetches and returns all known prices
  */
 export const findAll = async (): Promise<Prices> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let priceRows = [];
 	try {
 		const rows = await conn.query('SELECT price_id, product_id, v.vendor_id, price_in_cents, timestamp FROM prices p LEFT OUTER JOIN vendors v ON v.vendor_id = p.vendor_id WHERE active_listing = true AND v.isActive = true');
@@ -44,6 +44,9 @@ export const findAll = async (): Promise<Prices> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return priceRows;
@@ -54,7 +57,7 @@ export const findAll = async (): Promise<Prices> => {
  * @param id The id of the price to fetch
  */
 export const find = async (id: number): Promise<Price> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let price: any;
 	try {
 		const rows = await conn.query('SELECT price_id, product_id, p.vendor_id, price_in_cents, timestamp FROM prices p LEFT OUTER JOIN vendors v ON v.vendor_id = p.vendor_id WHERE price_id = ? AND active_listing = true AND v.isActive = true', id);
@@ -66,6 +69,9 @@ export const find = async (id: number): Promise<Price> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return price;
@@ -76,7 +82,7 @@ export const find = async (id: number): Promise<Price> => {
  * @param product the product to fetch the prices for
  */
 export const findByProduct = async (product: number): Promise<Prices> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let priceRows = [];
 	try {
 		const rows = await conn.query('SELECT price_id, product_id, p.vendor_id, price_in_cents, timestamp FROM prices p LEFT OUTER JOIN vendors v ON v.vendor_id = p.vendor_id WHERE product_id = ? AND active_listing = true AND v.isActive = true', product);
@@ -88,6 +94,9 @@ export const findByProduct = async (product: number): Promise<Prices> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return priceRows;
@@ -102,7 +111,7 @@ export const findByProduct = async (product: number): Promise<Prices> => {
  * @param type The type of prices, e.g. newest / lowest
  */
 export const findByType = async (product: string, type: string): Promise<Prices> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let priceRows = [];
 	try {
 		let rows = [];
@@ -138,6 +147,9 @@ export const findByType = async (product: string, type: string): Promise<Prices>
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return priceRows;
@@ -153,7 +165,7 @@ export const findByType = async (product: string, type: string): Promise<Prices>
  * @param type The type of prices, e.g. newest / lowest
  */
 export const findByVendor = async (product: string, vendor: string, type: string): Promise<Prices> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let priceRows = [];
 	try {
 		let rows = [];
@@ -176,6 +188,9 @@ export const findByVendor = async (product: string, vendor: string, type: string
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return priceRows;
@@ -187,7 +202,7 @@ export const findByVendor = async (product: string, vendor: string, type: string
  * @param amount The amount of deals to return
  */
 export const getBestDeals = async (amount: number): Promise<Prices> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let priceRows = [];
 	try {
 		let allPrices: Record<number, Price[]> = {};
@@ -268,6 +283,9 @@ export const getBestDeals = async (amount: number): Promise<Prices> => {
 	} catch (err) {
 		console.log(err);
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return priceRows;
@@ -278,7 +296,7 @@ export const getBestDeals = async (amount: number): Promise<Prices> => {
  * @param productIds the ids of the products
  */
 export const findListByProducts = async (productIds: [number]): Promise<Prices> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let priceRows: Price[] = [];
 	try {
 		let allPrices: Record<number, Price[]> = {};
@@ -325,13 +343,16 @@ export const findListByProducts = async (productIds: [number]): Promise<Prices>
 		});
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return priceRows;
 };
 
 export const createPriceEntry = async (user_id: number, vendor_id: number, product_id: number, price_in_cents: number): Promise<Boolean> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		// Check if the user is authorized to manage the requested vendor
 		const user_vendor_rows = await conn.query('SELECT vendor_id FROM vendors WHERE vendor_id = ? AND admin_id = ?', [vendor_id, user_id]);
@@ -346,5 +367,8 @@ export const createPriceEntry = async (user_id: number, vendor_id: number, produ
 		return res.affectedRows === 1;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/betterzon/products/products.service.ts

@@ -19,7 +19,7 @@ dotenv.config();
  * Fetches and returns all known products
  */
 export const findAll = async (): Promise<Products> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let prodRows = [];
 	try {
 		const rows = await conn.query('SELECT product_id, name, asin, is_active, short_description, long_description, image_guid, date_added, last_modified, manufacturer_id, selling_rank, category_id FROM products');
@@ -59,6 +59,9 @@ export const findAll = async (): Promise<Products> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return prodRows;
@@ -69,7 +72,7 @@ export const findAll = async (): Promise<Products> => {
  * @param id The id of the product to fetch
  */
 export const find = async (id: number): Promise<Product> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let prod: any;
 	try {
 		const rows = await conn.query('SELECT product_id, name, asin, is_active, short_description, long_description, image_guid, date_added, last_modified, manufacturer_id, selling_rank, category_id FROM products WHERE product_id = ?', id);
@@ -81,6 +84,9 @@ export const find = async (id: number): Promise<Product> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return prod;
@@ -91,7 +97,7 @@ export const find = async (id: number): Promise<Product> => {
  * @param term the term to match
  */
 export const findBySearchTerm = async (term: string): Promise<Products> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let prodRows = [];
 	try {
 		term = '%' + term + '%';
@@ -105,6 +111,9 @@ export const findBySearchTerm = async (term: string): Promise<Products> => {
 	} catch (err) {
 		console.log(err);
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return prodRows;
@@ -115,7 +124,7 @@ export const findBySearchTerm = async (term: string): Promise<Products> => {
  * @param ids The list of product ids to fetch the details for
  */
 export const findList = async (ids: [number]): Promise<Products> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let prodRows = [];
 	try {
 		const rows = await conn.query('SELECT product_id, name, asin, is_active, short_description, long_description, image_guid, date_added, last_modified, manufacturer_id, selling_rank, category_id FROM products WHERE product_id IN (?)', [ids]);
@@ -127,6 +136,9 @@ export const findList = async (ids: [number]): Promise<Products> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return prodRows;
@@ -137,7 +149,7 @@ export const findList = async (ids: [number]): Promise<Products> => {
  * @param id The id of the vendor to fetch the products for
  */
 export const findByVendor = async (id: number): Promise<Products> => {
-    let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let prodRows = [];
 	try {
 		// Get the relevant product ids
@@ -159,6 +171,9 @@ export const findByVendor = async (id: number): Promise<Products> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return prodRows;

src/models/betterzon/users/users.service.ts

@@ -21,7 +21,7 @@ dotenv.config();
  * Creates a user record in the database, also creates a session. Returns the session if successful.
  */
 export const createUser = async (username: string, password: string, email: string, ip: string): Promise<Session> => {
-	let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		// Hash password and generate + hash session key
 		const pwHash = bcrypt.hashSync(password, 10);
@@ -63,6 +63,9 @@ export const createUser = async (username: string, password: string, email: stri
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -71,7 +74,7 @@ export const createUser = async (username: string, password: string, email: stri
  * Returns the session information in case of a successful login
  */
 export const login = async (username: string, password: string, ip: string): Promise<Session> => {
-	let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		// Get saved password hash
 		const query = 'SELECT user_id, bcrypt_password_hash FROM users WHERE username = ?';
@@ -123,6 +126,9 @@ export const login = async (username: string, password: string, ip: string): Pro
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -130,7 +136,7 @@ export const login = async (username: string, password: string, ip: string): Pro
  * Checks if the given session information are valid and returns the user information if they are
  */
 export const checkSession = async (sessionId: string, sessionKey: string, ip: string): Promise<User> => {
-	let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		// Get saved session key hash
 		const query = 'SELECT user_id, session_key_hash, validUntil FROM sessions WHERE session_id = ?';
@@ -198,6 +204,9 @@ export const checkSession = async (sessionId: string, sessionKey: string, ip: st
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -230,7 +239,7 @@ export interface Status {
  * @param email The email to check
  */
 export const checkUsernameAndEmail = async (username: string, email: string): Promise<Status> => {
-	let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		// Create user entry in SQL
 		const usernameQuery = 'SELECT username FROM users WHERE username = ?';
@@ -278,5 +287,8 @@ export const checkUsernameAndEmail = async (username: string, email: string): Pr
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/betterzon/vendors/vendors.service.ts

@@ -18,7 +18,7 @@ dotenv.config();
  * Fetches and returns all known vendors
  */
 export const findAll = async (): Promise<Vendors> => {
-	let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let vendorRows = [];
 	try {
 		const rows = await conn.query('SELECT vendor_id, name, streetname, zip_code, city, country_code, phone, website FROM vendors WHERE isActive = true');
@@ -50,6 +50,9 @@ export const findAll = async (): Promise<Vendors> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return vendorRows;
@@ -60,7 +63,7 @@ export const findAll = async (): Promise<Vendors> => {
  * @param id The id of the vendor to fetch
  */
 export const find = async (id: number): Promise<Vendor> => {
-	let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let vendor: any;
 	try {
 		const rows = await conn.query('SELECT vendor_id, name, streetname, zip_code, city, country_code, phone, website FROM vendors WHERE vendor_id = ? AND isActive = true', id);
@@ -72,6 +75,9 @@ export const find = async (id: number): Promise<Vendor> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return vendor;
@@ -82,7 +88,7 @@ export const find = async (id: number): Promise<Vendor> => {
  * @param term the term to match
  */
 export const findBySearchTerm = async (term: string): Promise<Vendors> => {
-	let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let vendorRows = [];
 	try {
 		term = '%' + term + '%';
@@ -95,6 +101,9 @@ export const findBySearchTerm = async (term: string): Promise<Vendors> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return vendorRows;
@@ -105,7 +114,7 @@ export const findBySearchTerm = async (term: string): Promise<Vendors> => {
  * @param user The user to return the managed shops for
  */
 export const getManagedShops = async (user_id: number): Promise<Vendors> => {
-	let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	let vendorRows = [];
 	try {
 		const rows = await conn.query('SELECT vendor_id, name, streetname, zip_code, city, country_code, phone, website FROM vendors WHERE admin_id LIKE ?', user_id);
@@ -117,6 +126,9 @@ export const getManagedShops = async (user_id: number): Promise<Vendors> => {
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 
 	return vendorRows;
@@ -129,7 +141,7 @@ export const getManagedShops = async (user_id: number): Promise<Vendors> => {
  * @param product_id The product id of the product to deactivate the listing for
  */
 export const deactivateListing = async (user_id: number, vendor_id: number, product_id: number): Promise<Boolean> => {
-	let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		// Check if the user is authorized to manage the requested vendor
 		const user_vendor_rows = await conn.query('SELECT vendor_id FROM vendors WHERE vendor_id = ? AND admin_id = ?', [vendor_id, user_id]);
@@ -142,6 +154,9 @@ export const deactivateListing = async (user_id: number, vendor_id: number, prod
 		return status.affectedRows > 0;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -152,7 +167,7 @@ export const deactivateListing = async (user_id: number, vendor_id: number, prod
  * @param isActive The new active state
  */
 export const setShopStatus = async (user_id: number, vendor_id: number, isActive: boolean): Promise<Boolean> => {
-	let conn = BetterzonDB.getConnection();
+	let conn = await BetterzonDB.getConnection();
 	try {
 		// Check if the user is authorized to manage the requested vendor
 		const user_vendor_rows = await conn.query('SELECT vendor_id FROM vendors WHERE vendor_id = ? AND admin_id = ?', [vendor_id, user_id]);
@@ -166,5 +181,8 @@ export const setShopStatus = async (user_id: number, vendor_id: number, isActive
 		return status.affectedRows > 0;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/climbing-route-rating/ClimbingRouteRating.db.ts

@@ -13,7 +13,7 @@ export namespace ClimbingRouteRatingDB {
 		connectionLimit: 5
 	});
 
-    export function getConnection() {
-        return pool;
-    }
+	export const getConnection = async () => {
+		return pool.getConnection();
+	};
 }

src/models/climbing-route-rating/climbing_gyms/climbingGyms.service.ts

@@ -6,11 +6,14 @@ import {ClimbingGym} from './ClimbingGym.interface';
  * @return Promise<ClimbingHall[]> The climbing halls
  */
 export const findAll = async (): Promise<ClimbingGym[]> => {
-    let conn = ClimbingRouteRatingDB.getConnection();
+	let conn = await ClimbingRouteRatingDB.getConnection();
 	try {
 		return await conn.query('SELECT gym_id, name, city, verified FROM climbing_gyms');
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -21,7 +24,7 @@ export const findAll = async (): Promise<ClimbingGym[]> => {
  * @return number The id of the climbing hall
  */
 export const createGym = async (name: string, city: string): Promise<number> => {
-    let conn = ClimbingRouteRatingDB.getConnection();
+	let conn = await ClimbingRouteRatingDB.getConnection();
 
 	try {
 		let res = await conn.query('INSERT INTO climbing_gyms (name, city) VALUES (?, ?) RETURNING gym_id', [name, city]);
@@ -29,5 +32,8 @@ export const createGym = async (name: string, city: string): Promise<number> =>
 		return res[0].gym_id;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/climbing-route-rating/climbing_routes/climbingRoutes.service.ts

@@ -7,11 +7,14 @@ import random from 'random-words';
  * @return Promise<ClimbingRoute[]> The climbing routes
  */
 export const findAll = async (): Promise<ClimbingRoute[]> => {
-    let conn = ClimbingRouteRatingDB.getConnection();
+	let conn = await ClimbingRouteRatingDB.getConnection();
 	try {
 		return await conn.query('SELECT route_id, gym_id, name, difficulty, route_setting_date FROM climbing_routes');
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -21,11 +24,14 @@ export const findAll = async (): Promise<ClimbingRoute[]> => {
  * @return Promise<ClimbingRoute> The climbing route
  */
 export const findById = async (route_id: string): Promise<ClimbingRoute> => {
-    let conn = ClimbingRouteRatingDB.getConnection();
+	let conn = await ClimbingRouteRatingDB.getConnection();
 	try {
 		return await conn.query('SELECT route_id, gym_id, name, difficulty, route_setting_date FROM climbing_routes WHERE route_id = ?', route_id);
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -37,7 +43,7 @@ export const findById = async (route_id: string): Promise<ClimbingRoute> => {
  * @return string The id of the created route
  */
 export const createRoute = async (gym_id: number, name: string, difficulty: string): Promise<string> => {
-    let conn = ClimbingRouteRatingDB.getConnection();
+	let conn = await ClimbingRouteRatingDB.getConnection();
 
 	// Generate route id
 	let route_id = '';
@@ -55,5 +61,8 @@ export const createRoute = async (gym_id: number, name: string, difficulty: stri
 		return route_id;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/climbing-route-rating/route_comments/routeComments.service.ts

@@ -6,11 +6,14 @@ import {RouteComment} from './RouteComment.interface';
  * @return Promise<RouteComment[]> The comments
  */
 export const findByRoute = async (route_id: string): Promise<RouteComment[]> => {
-    let conn = ClimbingRouteRatingDB.getConnection();
+	let conn = await ClimbingRouteRatingDB.getConnection();
 	try {
 		return await conn.query('SELECT comment_id, route_id, comment, timestamp FROM route_comments WHERE route_id = ?', route_id);
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -21,12 +24,15 @@ export const findByRoute = async (route_id: string): Promise<RouteComment[]> =>
  * @return number The id of the comment
  */
 export const createComment = async (route_id: string, comment: string): Promise<number> => {
-    let conn = ClimbingRouteRatingDB.getConnection();
+	let conn = await ClimbingRouteRatingDB.getConnection();
 	try {
 		let res = await conn.query('INSERT INTO route_comments (route_id, comment) VALUES (?, ?) RETURNING comment_id', [route_id, comment]);
 
 		return res[0].comment_id;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/climbing-route-rating/route_ratings/routeRatings.service.ts

@@ -7,11 +7,14 @@ import {RouteRating} from './RouteRating.interface';
  * @return Promise<RouteRating[]> The ratings
  */
 export const findByRoute = async (route_id: string): Promise<RouteRating[]> => {
-    let conn = ClimbingRouteRatingDB.getConnection();
+	let conn = await ClimbingRouteRatingDB.getConnection();
 	try {
 		return await conn.query('SELECT rating_id, route_id, stars, timestamp FROM route_ratings WHERE route_id = ?', route_id);
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -41,12 +44,15 @@ export const getStarsForRoute = async (route_id: string): Promise<number> => {
  * @return number The id of the created rating
  */
 export const createRating = async (route_id: string, stars: number): Promise<number> => {
-    let conn = ClimbingRouteRatingDB.getConnection();
+	let conn = await ClimbingRouteRatingDB.getConnection();
 	try {
 		let res = await conn.query('INSERT INTO route_ratings (route_id, stars) VALUES (?, ?) RETURNING rating_id', [route_id, stars]);
 
 		return res[0].comment_id;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/dhbw-rapla-changes/DHBWRaPlaChanges.db.ts

@@ -13,7 +13,7 @@ export namespace RaPlaChangesDB {
 		connectionLimit: 5
 	});
 
-    export function getConnection() {
-        return pool;
-    }
+	export const getConnection = async () => {
+		return pool.getConnection();
+	};
 }

src/models/dhbw-rapla-changes/changes/changes.service.ts

@@ -6,7 +6,7 @@ import {RaPlaChangesDB} from '../DHBWRaPlaChanges.db';
 dotenv.config();
 
 export const getChanges = async (course: string, week: string): Promise<Event[]> => {
-    let conn = RaPlaChangesDB.getConnection();
+	let conn = await RaPlaChangesDB.getConnection();
 	try {
 		let relevantEventsRows = await conn.query('SELECT DISTINCT(entry_id) FROM rapla_changes WHERE new_start > ? AND new_start < DATE_ADD(?, INTERVAL 7 DAY)', [week, week]);
 
@@ -68,11 +68,14 @@ export const getChanges = async (course: string, week: string): Promise<Event[]>
 		return Array.from(eventsMap.values()) as Event[];
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
 export const getEventById = async (course: string, id: string): Promise<Event> => {
-    let conn = RaPlaChangesDB.getConnection();
+	let conn = await RaPlaChangesDB.getConnection();
 	try {
 		let rows = await conn.query('SELECT c.change_id, c.entry_id, c.change_timestamp, c.isDeleted, c.new_summary, c.new_description, c.new_start, c.new_last_modified, c.new_end, c.new_created, c.new_location, c.new_organizer, c.new_categories, e.uid FROM rapla_changes c LEFT OUTER JOIN rapla_entries e ON c.entry_id = e.entry_id WHERE e.uid = ? ORDER BY c.change_id', id);
 
@@ -123,5 +126,8 @@ export const getEventById = async (course: string, id: string): Promise<Event> =
 		return Array.from(eventsMap.values())[0];
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/partyplaner/PartyPlaner.db.ts

@@ -20,10 +20,10 @@ export namespace PartyPlanerDB {
 		connectionLimit: 5
 	});
 
-    export function getConnection(useDev: boolean = false) {
+	export const getConnection = async (useDev: boolean = false) => {
 		if (useDev) {
-            return dev_pool;
-        }
-        return prod_pool;
+			return dev_pool.getConnection();
 		}
+		return prod_pool.getConnection();
+	};
 }

src/models/partyplaner/event/event.service.ts

@@ -11,7 +11,7 @@ dotenv.config();
  * @return Event[] A list of events
  */
 export const getEventData = async (useDev: boolean, userId: string): Promise<Event[]> => {
-    let conn = PartyPlanerDB.getConnection(useDev);
+	let conn = await PartyPlanerDB.getConnection(useDev);
 	try {
 		let eventRows = await conn.query('SELECT event_id, name, description, takes_place_date, registration_until_date, max_participants FROM events WHERE creator_id = ?', userId);
 
@@ -69,5 +69,8 @@ export const getEventData = async (useDev: boolean, userId: string): Promise<Eve
 		return eventsList;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/partyplaner/friendship/friendship.service.ts

@@ -11,7 +11,7 @@ dotenv.config();
  * @return Friendship[] A list of friends
  */
 export const getFriendshipData = async (useDev: boolean, userId: string): Promise<Friendship[]> => {
-    let conn = PartyPlanerDB.getConnection(useDev);
+	let conn = await PartyPlanerDB.getConnection(useDev);
 	try {
 		let rows = await conn.query('SELECT f.friendship_id, f.friend_id, u.first_name as friend_first_name, u.last_name as friend_last_name, u.username as friend_username FROM friendships f LEFT OUTER JOIN users u ON f.friend_id = u.user_id WHERE f.user_id = ?', userId);
 
@@ -30,5 +30,8 @@ export const getFriendshipData = async (useDev: boolean, userId: string): Promis
 		return friends;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/partyplaner/invite/invite.service.ts

@@ -11,7 +11,7 @@ dotenv.config();
  * @return ReceivedInvite[] A list of invites
  */
 export const getInvitesData = async (useDev: boolean, userId: string): Promise<ReceivedInvite[]> => {
-    let conn = PartyPlanerDB.getConnection(useDev);
+	let conn = await PartyPlanerDB.getConnection(useDev);
 	try {
 		let rows = await conn.query('SELECT i.invite_id, i.valid_until, i.already_used, i.invite_key, e.name as event_name, e.description as event_description, e.takes_place_date, e.registration_until_date, e.max_participants, e.creator_id, u.first_name, u.last_name FROM invitations i LEFT OUTER JOIN events e ON e.event_id = i.event_id LEFT OUTER JOIN users u ON u.user_id = e.creator_id WHERE i.user_id = ?', userId);
 
@@ -37,5 +37,8 @@ export const getInvitesData = async (useDev: boolean, userId: string): Promise<R
 		return invites;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/partyplaner/session/session.service.ts

@@ -11,7 +11,7 @@ dotenv.config();
  * @return SessionData[] A list containing objects with the session data
  */
 export const getSessionData = async (useDev: boolean, userId: string): Promise<SessionData[]> => {
-    let conn = PartyPlanerDB.getConnection(useDev);
+	let conn = await PartyPlanerDB.getConnection(useDev);
 	try {
 		let rows = await conn.query('SELECT session_id, type, last_login, last_ip FROM sessions WHERE user_id = ? AND valid_until > NOW()', userId);
 
@@ -29,5 +29,8 @@ export const getSessionData = async (useDev: boolean, userId: string): Promise<S
 		return sessions;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/partyplaner/user/user.service.ts

@@ -15,7 +15,7 @@ dotenv.config();
  * @return UserData An object containing the user data
  */
 export const getUserData = async (useDev: boolean, userId: string): Promise<UserData> => {
-    let conn = PartyPlanerDB.getConnection(useDev);
+	let conn = await PartyPlanerDB.getConnection(useDev);
 	try {
 		let rows = await conn.query('SELECT username, email, first_name, last_Name, last_login, email_is_verified, is_premium_user FROM users WHERE user_id = ?', userId);
 
@@ -36,6 +36,9 @@ export const getUserData = async (useDev: boolean, userId: string): Promise<User
 		return user;
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -45,7 +48,7 @@ export const getUserData = async (useDev: boolean, userId: string): Promise<User
  * @return any An object with a list of usernames and emails
  */
 export const getExistingUsernamesAndEmails = async (useDev: boolean): Promise<any> => {
-    let conn = PartyPlanerDB.getConnection(useDev);
+	let conn = await PartyPlanerDB.getConnection(useDev);
 	try {
 		const rows = await conn.query('SELECT username, email FROM users');
 
@@ -63,6 +66,9 @@ export const getExistingUsernamesAndEmails = async (useDev: boolean): Promise<an
 		};
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -78,7 +84,7 @@ export const getExistingUsernamesAndEmails = async (useDev: boolean): Promise<an
  * @param deviceInfo The user agent of the new user
  */
 export const registerUser = async (useDev: boolean, username: string, email: string, firstName: string, lastName: string, password: string, ip: string, deviceInfo: string): Promise<Session> => {
-    let conn = PartyPlanerDB.getConnection(useDev);
+	let conn = await PartyPlanerDB.getConnection(useDev);
 	try {
 		const pwHash = bcrypt.hashSync(password, 10);
 		const sessionKey = Guid.create().toString();
@@ -125,6 +131,9 @@ export const registerUser = async (useDev: boolean, username: string, email: str
 		};
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -138,7 +147,7 @@ export const registerUser = async (useDev: boolean, username: string, email: str
  * @param deviceInfo The user agent of the new user
  */
 export const loginUser = async (useDev: boolean, username: string, email: string, password: string, ip: string, deviceInfo: string): Promise<Session> => {
-    let conn = PartyPlanerDB.getConnection(useDev);
+	let conn = await PartyPlanerDB.getConnection(useDev);
 	try {
 		let query_result;
 
@@ -197,6 +206,9 @@ export const loginUser = async (useDev: boolean, username: string, email: string
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
@@ -207,7 +219,7 @@ export const loginUser = async (useDev: boolean, username: string, email: string
  * @param email The email to check
  */
 export const checkUsernameAndEmail = async (useDev: boolean, username: string, email: string): Promise<Status> => {
-    let conn = PartyPlanerDB.getConnection(useDev);
+	let conn = await PartyPlanerDB.getConnection(useDev);
 	try {
 		const usernameQuery = 'SELECT username FROM users WHERE username = ?';
 		const emailQuery = 'SELECT email FROM users WHERE email = ?';
@@ -254,11 +266,14 @@ export const checkUsernameAndEmail = async (useDev: boolean, username: string, e
 
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };
 
 export const checkSession = async (useDev: boolean, userId: string, sessionId: string, sessionKey: string): Promise<boolean> => {
-    let conn = PartyPlanerDB.getConnection(useDev);
+	let conn = await PartyPlanerDB.getConnection(useDev);
 	try {
 		let rows = await conn.query('SELECT session_key_hash FROM sessions WHERE user_id = ? AND session_id = ?', [userId, sessionId]);
 
@@ -270,5 +285,8 @@ export const checkSession = async (useDev: boolean, userId: string, sessionId: s
 		return bcrypt.compareSync(sessionKey, savedHash);
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };

src/models/twitch-highlight-marker/HighlightMarker.db.ts

@@ -13,7 +13,7 @@ export namespace HighlightMarkerDB {
 		connectionLimit: 5
 	});
 
-    export function getConnection() {
-        return pool;
-    }
+	export const getConnection = async () => {
+		return pool.getConnection();
+	};
 }

src/models/twitch-highlight-marker/addHighlight/addHighlights.service.ts

@@ -8,7 +8,7 @@ dotenv.config();
  * @param req_body The request body
  */
 export const createHighlightEntry = async (req_body: any) => {
-    let conn = HighlightMarkerDB.getConnection();
+	let conn = await HighlightMarkerDB.getConnection();
 	try {
 		const streamers = await conn.query('SELECT streamer_id FROM streamers WHERE username = ?', req_body.streamer);
 		let streamer_id: number = -1;
@@ -24,5 +24,8 @@ export const createHighlightEntry = async (req_body: any) => {
 		const rows = await conn.query('INSERT INTO highlights (streamer_id, stream_id, description, stream_timestamp, issuing_user, game) VALUES (?, ?, ?, ?, ?, ?)', params);
 	} catch (err) {
 		throw err;
+	} finally {
+		// Return connection
+		await conn.end();
 	}
 };