Hello guys, welcome to the second session of create custom Alexa skills using AWS lambda function tutorial for beginners. In this session we will learn how to use dynamodb. Within Alexa. Amazon Dynamo DB is a fast and flexible, no SQL database service. It's part of AWS dynamodb supports both document and key value store model. Alexa SDK provides methods to store and retrieve data from dynamodb easily.

Alexa core SDK use user ID as the partition key. Let us open AWS console. Search for Dynamo dB. Click on create table button. Use table name that you want to use. For a partition key, we need to write it it will be you Already from the request it will be a string and click on Create button in our table is creating it takes time.

In between I'm going to add Dynamo DB permissions to our lambda function. For this open a click on rules go down to bottom search for a library that you have created. So here we need to search for thought selected click on attach policy button. Search for Dynamo and select Amazon dynamodb full access click on attach policy by Yes, it was attached successfully. In a session, I will use the same intent of user preference. Now, we will add those slot values into session.

When the user saves save my data, then we will save those data into dynamodb. And when the user says show me data, we will retrieve it from the database. Let us create new intent. With name save user preference. Here the user may say to my preferences, store data and create one more intent with same show user preference. For this user may say, Show user data or show me preference.

That is the model Let us switch to Visual Studio code to update our lambda. In add user preference handler, we will add those lock values into sessions. For this, let us return accessing data using attribute manager. And update values for all those three slots. And using set session attributes method, update session data. So we don't want to end session here, so use with short end session methods and commend those LSA and confirm slot conditions.

So we can simply test for This example, we also need to use Alexa SDK along with core SAP. So let us install this. To use Dynamo DB in Alexa SDK, we need to install AWS SDK as well as Dynamo DB persistence adapter. Change name to Alexa code as it will load code package. Let us import all three packages that we have installed chrome to end here we need to create an instance of standard scale instead. of customs key difference between standard scale and custom scale is that standard scale includes some methods for managing dynamodb data.

Use with table name method of standard scale builder and pass table name that we have created. Let me cooperate in with the Dynamo DB client method create instance of Dynamo DB and use latest API volume in which partition key generator method pass user ID. We can also use device ID. Now let us create a new handler for save user preference intent. Forgot to append handle suffix however it is not necessary. Here we need to create a new promise and retain existing attributes from database using get persistent attributes method of attributes furniture.

We will get Dynamo attributes often session data and upgrade dynamite attributes with session. Use set persistent attributes method to update those attributes. I'll see you positioned persistent attribute method and pass handler in And I know what troubles we will need to return this year is a typo, we need to use them instead of them. After saving those attributes, we need to generate a simple response with the message your data saved successfully. Open skill again to check those data and passes into resolve method that we get in roles. Create catch method and past error object in recheck method.

Now we need to create new handler for save user preference intent. That is copy this handler. Update intending. Let us remove this unnecessary code and generate speech text. A person name you want to visit country name. with Frank count spreads a great inspect method register both handlers.

Save the file and deploy lambda function. Open test simulator data reskin My name is Abby and I want to visit the web with my two friends. You can see that data is added to session attributes. That is save those data in Dynamo dB. Here an error occurred Let us open cloud watch to see refresh log groups select latest lock string your session was ended because that response was null it means our lambda function didn't generate response. Let us see what is missing.

Here we have called get response we also need to return promise. Also update this in show yourself preference handler and deploy lambda function again opensky again use same utterance and same preference. Here we call it a success message. That is say in dynamodb Nick on item. Here isn't our record expanded attributes, those three values are we have added for this user ID. Let us use same attributes and change value of any slot.

Now Emily want to visit Australia Here we need to start our skill again. We had a good session after saving data. You same segment and save data checking dynamodb click on Search to reload data. Here you can see that we are Australia in country name attribute means dynamodb will perform update operation if it contains values with same user ID. Let us check those values from simulator. Again, we need to open our escape and this time directly open show user preference intent.

Here we got all the news as we have expected Now, let's Important we are learning this session dynamodb is no SQL database we can throw in key value formula. To use Dynamo DB in Alexa core SDK we need to install AWS SDK and Dynamo DB persistence and create a table in Dynamo DB with partition key Id use standard skills built in which table a method pass table name. In with Dynamo DB client method create instance of Dynamo DB in which partition key generator method specify a key that you want to use a silk reference handler. Here we have created promise and return existing data by using set persisting attributes microsite data and save persistent attributes method to save those data. After this we have generated a response and classic in his own mind. Here is show you the preference handle Again here we need to use promise.

Use get persistent attributes method to obtain all attributes and generate a string for speech and pass it in resolve matters. Thanks for watching this video. If you have any doubt, please feel free to contact me otherwise