diff --git a/idb.js b/idb.js
index 7c7eb5c..512ba6f 100644
--- a/idb.js
+++ b/idb.js
@@ -1,12 +1,12 @@
 /*!
- * idb.js IndexedDB wrapper v3.1
+ * idb.js IndexedDB wrapper v3.2
  * Licensed under the MIT license
  * Copyright (c) 2023 Lukas Jans
  * https://github.com/ljans/idb
  */
 class IDB {
 	
-	// Wrap IDBRequest im promise
+	// Wrap IDBRequest in promise
 	promise(request) {
 		return new Promise((resolve, reject) => {
 			request.onerror = () => reject(request.error);
@@ -16,29 +16,44 @@ class IDB {
 	
 	// Constructor
 	constructor(tables, config={}) {
+		this.tables = tables;
+		this.config = config;
 		
-		// Connect to DB
-		const request = indexedDB.open(config.name || 'IDB', config.version || 1);
-		this.connection = this.promise(request);
-			
-		// Perform upgrade
-		request.onupgradeneeded = e => {
+		// Bind table controllers
+		for(const name of Object.keys(tables)) this[name] = new this.Table(name, this);
+		
+		// Establish an initial connection to catch upgrade events
+		//this.connection.then(db => db.close());
+	}
+	
+	// Establish a db connection
+	get connection() {
+		const request = indexedDB.open(this.config.name || 'IDB', this.config.version || 1);
+		
+		/**
+		 * Always check for an upgade event, because querying a table when the database does not exists
+		 * (either because it was deleted or initial creation is commented out in the constructor)
+		 * causes indexedDB.open to create the database without any tables until another upgrade happens.
+		 */
+		request.onupgradeneeded = async e => {
 			const db = request.result;
 			
 			// Clear old tables
-			for(const name of db.objectStoreNames) if(!tables[name]) db.deleteObjectStore(name);
+			for(const name of db.objectStoreNames) if(!this.tables[name]) db.deleteObjectStore(name);
 			
 			// Create new tables
-			for(const [name, options] of Object.entries(tables)) if(!db.objectStoreNames.contains(name)) db.createObjectStore(name, options);
+			for(const [name, options] of Object.entries(this.tables)) {
+				if(!db.objectStoreNames.contains(name)) db.createObjectStore(name, options);
+			}
 			
 			// Bubble upgrade event
-			if(config.upgrade) config.upgrade(e);
+			if(this.config.upgrade) await this.config.upgrade(e);
 		}
 		
-		// Bind table controllers
-		for(const name of Object.keys(tables)) this[name] = new this.Table(name, this);
+		// Return a promise that resolves to the established connection
+		return this.promise(request);
 	}
-	
+
 	// Table controller
 	get Table() {
 		return class {
@@ -49,18 +64,20 @@ class IDB {
 				this.instance = instance;
 			}
 			
-			// Perform operation in transaction
-			transaction(operation) {
-				return this.instance.connection.then(db => {
-					
-					// Retrieve operation result
-					const transaction = db.transaction(this.name, 'readwrite');
-					const table = transaction.objectStore(this.name);
-					const result = operation(table);
-					
-					// Return promise or wrap IDBRequest in promise
-					return result instanceof Promise ? result : this.instance.promise(result);
-				});
+			// Perform operation in transaction (commit transaction and close connection so it's always possible to delete the db)
+			async transaction(operation) {
+				const db = await this.instance.connection;
+				
+				// Perform the operation
+				const transaction = db.transaction(this.name, 'readwrite');
+				const table = transaction.objectStore(this.name);
+				var result = await operation(table);
+				transaction.commit();
+				
+				// Wait for result and close connection
+				if(result instanceof IDBRequest) result = await this.instance.promise(result);
+				db.close();
+				return result;
 			}	
 			
 			// Read data by index