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‫So now we want to add a DynamoDB table

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‫to our whole serverless docs to really make

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‫our app fully serverless.

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‫So, let's go back to the code we had from before.

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‫And so as we can see, we have DynamoDB already in it.

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‫So, this sounds about right.

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00:00:16,250 --> 00:00:21,250
‫So, let's go ahead and basically copy this code right here

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00:00:21,370 --> 00:00:23,520
‫and we're going to load the function.

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00:00:23,520 --> 00:00:26,370
‫And, here we create our boto3 clients.

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00:00:26,370 --> 00:00:29,910
‫So, something you do note is that we create the client

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‫outside of the handler.

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‫So, this is again, if you remember,

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‫one of the best practice is to put the clients

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‫outside of your handler.

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‫It's very, very important.

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‫Here, we load the table name

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‫and the other thing we want to do is

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‫set this boto3 client to be in the region name we are in.

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‫So, here I'll say region name

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‫equals os.environ

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‫so we get another environ variable.

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‫And, this time it is going to be called region name.

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‫And, here I will say region name equals region name.

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‫So, basically we set our DynamoDB client

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‫to be equal to the region in which we deploy our function.

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‫As we can see now, we are

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‫referencing two environment variables,

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‫region name and table name.

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‫And, so we have to set them in the template.yaml.

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‫So, how do we do this.

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‫Let's have a look at how it was done in the examples file.

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‫So, this is our lambda function.

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‫We don't need this anymore.

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‫And, here is out template.yaml.

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‫And, so now we have to reference DynamoDB

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‫and so, as you can see in the bottom,

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‫there is a table that gets created for us

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‫and this table of type simple table.

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‫So, let's go ahead and copy this.

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‫So, we'll copy this simple table right here, okay table.

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00:01:46,680 --> 00:01:48,540
‫And, the type is a simple table

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‫but I want to set a few properties

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‫because I don't want this table to cost you a lot of money.

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00:01:52,820 --> 00:01:57,773
‫And, so if we type "simpletable serverless options,"

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‫that should be it.

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00:02:00,460 --> 00:02:05,460
‫Here, we go to simple table and we get the resource type,

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‫and so we get the different patterns we can use.

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‫One of them being, if you scroll down,

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‫the provisioned throughput.

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‫I want the provisioned throughput to be equal to one and one

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‫just so we have limited version throughput

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‫and we don't overwrite.

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‫We can also set a primary key,

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‫and so we can just copy this as well

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‫so we get a full simple table that is going to be working.

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‫So, let's copy these things.

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‫We have the primary key in with the provisioned throughput.

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‫The primary key is going to be called greeting

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‫and it's going to be a string.

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‫So, we just have a partition key.

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‫And, for the provisioned throughput,

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‫I said, well let's use two.

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‫Two and two.

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‫So, here is our simple table and so now we

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‫need to set environment variables for our lambda handler.

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‫For this, pretty easy.

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‫Again, let's go back and see how it was done.

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‫We use something called environment

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‫and in there we can reference the variables we want.

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‫So, let's just go to environment

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‫and we're going to set it right here, environment.

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‫And, I'll have to indent it, okay.

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‫The variables, the first one is going to be table name

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‫and I'm going to do a reference function,

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‫so ref, like an Intrinsic CloudFormation function,

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‫to the table that was created from before,

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‫this simple table.

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‫So, here we have table that's typed correctly

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‫and the other environment variable that I said

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‫is the region name.

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‫And, for this, I'll set reference to AWS region,

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‫which is a pseudo parameter, if you remember it,

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00:03:33,500 --> 00:03:35,610
‫this is a pseudo parameter that is provided

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‫directly by the AWS CloudFormation templates.

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‫Okay, so now we have our table name and our region name.

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‫And, we have created a table, but if you remember,

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‫when we do this, we need to give ourselves

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‫the lambda function the access to this simple table.

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‫For this, pretty easy.

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00:03:54,330 --> 00:03:57,140
‫Again, we go ahead and we need to add policies.

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‫And these policies are going to be

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‫IAM policies we can add on to our lambda function.

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00:04:02,030 --> 00:04:05,160
‫So, let's go and write our policies right here.

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00:04:05,160 --> 00:04:09,410
‫And the policy, once you add it, is DynamoDB crud policy.

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‫And, the table name we reference has to be

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‫for the table name that was created, so ref table.

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‫And, this will basically give us, okay,

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‫a DynamoDB policy that allows us to do crude operation

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‫on the table that was created.

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‫And, so we get the full IAM policy.

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00:04:28,490 --> 00:04:32,150
‫Now, in terms of what our application does, well,

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‫maybe we don't want to return "hello world."

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‫Maybe we want to do something

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‫a little bit more interesting here.

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‫So, we can use a scan operation.

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‫So, DyanmoDB,

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‫so dynamo

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‫dot

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‫scan

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00:04:43,890 --> 00:04:45,880
‫and then we have to reference a table name parameter,

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‫so table name equals,

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‫and we have to pass in the table name

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‫that we have retrieved from before.

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‫So, table name equals table name.

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00:04:52,680 --> 00:04:56,300
‫This is our scan result that is equals to this.

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‫And, this is what we are going to pass.

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‫We are going to respond with the scan result.

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00:05:01,950 --> 00:05:03,100
‫So, a pretty simple function.

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00:05:03,100 --> 00:05:06,410
‫We are just going to scan the table that was created.

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00:05:06,410 --> 00:05:08,300
‫So, that's it for our function.

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00:05:08,300 --> 00:05:11,080
‫It just scans, you know, our table

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00:05:11,080 --> 00:05:14,700
‫that is created from this simple table thing.

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00:05:14,700 --> 00:05:16,930
‫So, now let's go ahead and deploy our function,

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00:05:16,930 --> 00:05:20,923
‫so I'll just run these two things right here in my terminal.

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00:05:24,380 --> 00:05:25,751
‫And, so now we are in CloudFormation.

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00:05:25,751 --> 00:05:27,300
‫The cloud update is complete and if you look at

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‫the resources being created,

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‫we now have a DynamoDB table that was being created.

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00:05:33,160 --> 00:05:35,380
‫So, we have a table in DynamoDB.

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‫Let's go into DynamoDB to see how things are.

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‫So, DynamoDB,

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‫here we go.

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‫We go to tables, and here is my hello world sam table

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‫who has a partition key named greeting

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00:05:47,740 --> 00:05:50,070
‫and it has two read capacity units

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‫and two write capacity units.

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00:05:51,910 --> 00:05:54,880
‫Let's add a few items, so let's just create an item.

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00:05:54,880 --> 00:05:58,400
‫I'll say, greeting hello and then click on save.

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00:05:58,400 --> 00:05:59,660
‫This is our first greeting.

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00:05:59,660 --> 00:06:01,940
‫And, maybe I'll create another greeting called bonjour,

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00:06:01,940 --> 00:06:03,860
‫this is in my language, French.

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‫So, we have greeting in bonjour,

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00:06:04,960 --> 00:06:07,990
‫but you can have other greetings if you wanted to.

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00:06:07,990 --> 00:06:10,210
‫So, we have two elements in our DynamoDB table,

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‫which is pretty cool.

146
00:06:11,810 --> 00:06:13,200
‫And, now what we want to do

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‫is make sure that our function works properly.

148
00:06:16,110 --> 00:06:17,517
‫So, let's go to our lambda function

149
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‫and we'll refresh this page.

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‫And, now if we scroll down

151
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‫and look at the environment variables,

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‫we can see that the region name was

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‫automatically set to eu-west-3

154
00:06:27,870 --> 00:06:29,840
‫and our table name was automatically

155
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‫set to the table name that was created by DynamoDB.

156
00:06:32,290 --> 00:06:34,880
‫So, our environment variables are correctly set.

157
00:06:34,880 --> 00:06:37,750
‫And so, our code should be able to reference them.

158
00:06:37,750 --> 00:06:39,430
‫And, it turns out that our code

159
00:06:40,440 --> 00:06:42,860
‫has not been updated for some reason.

160
00:06:42,860 --> 00:06:43,693
‫Let's have a look.

161
00:06:43,693 --> 00:06:45,180
‫Nope, the code wasn't updated

162
00:06:45,180 --> 00:06:48,560
‫because I probably forgot to save the code.

163
00:06:48,560 --> 00:06:50,833
‫So, let's run this again.

164
00:06:53,310 --> 00:06:56,120
‫Okay, so my code is now updated, which is great.

165
00:06:56,120 --> 00:07:01,000
‫By the way, if you scroll down and look at the IAM role,

166
00:07:01,000 --> 00:07:04,240
‫it has created a hello world sam, hello world IAM role,

167
00:07:04,240 --> 00:07:07,980
‫so we could go to IAM to see what was done in there.

168
00:07:07,980 --> 00:07:08,930
‫So, lets go to IAM,

169
00:07:11,090 --> 00:07:12,560
‫click on that role,

170
00:07:12,560 --> 00:07:16,060
‫and here is the role that was created by hello world sam

171
00:07:16,060 --> 00:07:19,130
‫and it turns out it has a lambda basic execution role,

172
00:07:19,130 --> 00:07:22,290
‫which is great, and also an inline policy

173
00:07:22,290 --> 00:07:25,080
‫allowing it to do DynamoDB get item,

174
00:07:25,080 --> 00:07:27,590
‫delete item, put item, scan, etc.

175
00:07:27,590 --> 00:07:30,800
‫All on my hello world sam table.

176
00:07:30,800 --> 00:07:31,830
‫So, this is pretty awesome.

177
00:07:31,830 --> 00:07:34,220
‫So, sam framework just generated for us

178
00:07:34,220 --> 00:07:35,950
‫the DynamoDB, the API gateway,

179
00:07:35,950 --> 00:07:37,430
‫the lambda function, the IAM roles.

180
00:07:37,430 --> 00:07:38,970
‫Everything is perfect,

181
00:07:38,970 --> 00:07:43,240
‫so now hopefully if I go to my resources,

182
00:07:43,240 --> 00:07:45,960
‫to the GET route and test it out,

183
00:07:45,960 --> 00:07:49,300
‫I'll click on test and click on test again,

184
00:07:49,300 --> 00:07:51,980
‫I get a 200, so it works,

185
00:07:51,980 --> 00:07:54,290
‫and now it returns a response value,

186
00:07:54,290 --> 00:07:56,330
‫greeting hello, greeting bonjour.

187
00:07:56,330 --> 00:07:59,070
‫So, everything I add into my DynamoDB

188
00:07:59,070 --> 00:08:01,800
‫will just be returned by the API gateway.

189
00:08:01,800 --> 00:08:05,350
‫And so, overall that seems like a lot of things we did,

190
00:08:05,350 --> 00:08:07,890
‫but we just put together the API gateway,

191
00:08:07,890 --> 00:08:11,150
‫the lambda functions, the DynamoDB tables, the IAM policy.

192
00:08:11,150 --> 00:08:14,040
‫All together, such as now I have an API

193
00:08:14,040 --> 00:08:16,430
‫that I can call straight from Prod, for example.

194
00:08:16,430 --> 00:08:20,530
‫And, if I go to this url, prod slash hello,

195
00:08:20,530 --> 00:08:22,320
‫it will return to me all the greetings

196
00:08:22,320 --> 00:08:25,240
‫that are in my DynamoDB table and you could play

197
00:08:25,240 --> 00:08:28,400
‫and add more greetings here or remove them if you want.

198
00:08:28,400 --> 00:08:31,180
‫So, that's it for this lecture on DynamoDB table.

199
00:08:31,180 --> 00:08:33,893
‫I hope you liked it, and I will see you in the next one.