1 00:00:00,510 --> 00:00:06,620 In this video, we are going to develop create product method for product number microservices. 2 00:00:06,630 --> 00:00:09,030 We are using SDK libraries. 3 00:00:09,120 --> 00:00:15,630 So as you remember that in the last video we have accommodate the HTTP gate method with using the gate 4 00:00:15,630 --> 00:00:17,390 item command and scan command. 5 00:00:17,400 --> 00:00:20,550 But in this video we will focus on the post method. 6 00:00:20,550 --> 00:00:25,290 So a client sent us a http post request and lambda function. 7 00:00:25,290 --> 00:00:30,660 Accommodate the http post request in order to create a new item on Dynamo DB table. 8 00:00:31,170 --> 00:00:33,420 So please open the pseudocode. 9 00:00:33,420 --> 00:00:41,760 And this time as you can see that our switch statement only designed by the case operation to accommodate 10 00:00:41,760 --> 00:00:43,440 http gate method. 11 00:00:43,440 --> 00:00:50,970 So this time we will add additional case block which will be accommodate the HTTP post method in order 12 00:00:50,970 --> 00:00:54,450 to create a new item for that purpose. 13 00:00:54,450 --> 00:00:55,830 I'm going to. 14 00:00:57,610 --> 00:01:00,890 Come here and write the case below. 15 00:01:00,970 --> 00:01:04,150 As you can see that we have write the case post. 16 00:01:04,150 --> 00:01:08,260 So that means the event method will be the post. 17 00:01:08,260 --> 00:01:15,160 And in that case we will come here and run the great product method with passing the event object. 18 00:01:15,160 --> 00:01:16,540 So what is the event object? 19 00:01:16,540 --> 00:01:21,700 Event object the exact same that under the event you can see the post station. 20 00:01:21,790 --> 00:01:29,440 The event object is exact same with this structure which is the method as a post and you can see the 21 00:01:29,440 --> 00:01:33,580 resource and pet information if the method is posed. 22 00:01:33,580 --> 00:01:39,580 In that case we have an additional attribute which is the body attribute and in the body attribute we 23 00:01:39,580 --> 00:01:47,860 have as a JSON item format in the product JSON object and we will insert this item into dynamic DB table. 24 00:01:47,950 --> 00:01:56,110 So if you come back to our index case now, we have accommodate the HTTP post operation and run the 25 00:01:56,110 --> 00:01:59,500 create product method with passing these events JSON object. 26 00:01:59,500 --> 00:02:05,890 And after that I have added a default statement, which means if there is a string method that we don't 27 00:02:05,890 --> 00:02:10,990 cover in our switch statement, we can throw an exception with unsupported trout. 28 00:02:11,410 --> 00:02:16,720 Okay, now we can focus on this HTTP post operation before we implement the method. 29 00:02:16,720 --> 00:02:22,120 It is good to understand the command that we will use during the create product operation. 30 00:02:22,120 --> 00:02:28,390 If you open the SDK library documentation, you can see in here we will use put item command to perform 31 00:02:28,390 --> 00:02:29,320 create item. 32 00:02:29,320 --> 00:02:36,520 If you scroll down, you can see the example usage and see the command object and go to the input parameters 33 00:02:36,520 --> 00:02:41,860 and see the parameters that we will provide when inserting any item on Dynamo DB table. 34 00:02:42,160 --> 00:02:48,340 So please go back to our indexes and now we are going to implement create product method with passing 35 00:02:48,340 --> 00:02:49,840 the event JSON object. 36 00:02:49,870 --> 00:02:56,620 That means we will pass the event JSON object to get the body information and pass this item information 37 00:02:56,620 --> 00:02:58,660 to our command parameters. 38 00:02:58,660 --> 00:03:06,280 If you scroll down and go at the end of the page, we basically create a method which name is create 39 00:03:06,280 --> 00:03:07,030 product. 40 00:03:07,030 --> 00:03:09,100 So I'm going to copy and paste. 41 00:03:09,100 --> 00:03:11,890 After that I will be explained one by one. 42 00:03:11,950 --> 00:03:18,610 Here you can see the our method, which is the great product and is the async method to wait for the 43 00:03:18,610 --> 00:03:20,710 dynamic DB client send operation. 44 00:03:20,710 --> 00:03:24,490 And this time we will get event object as a parameter. 45 00:03:24,490 --> 00:03:31,150 And this event object is in here which is the post JSON and we will see exactly the same structure in 46 00:03:31,150 --> 00:03:31,930 this file. 47 00:03:31,960 --> 00:03:38,680 And basically before explaining this method, let me add the required import statement. 48 00:03:38,680 --> 00:03:44,770 So let's see one by one, if there is a required package, we can add. 49 00:03:46,360 --> 00:03:52,130 For example, Marshall we have already added dynamic declined object and this time we will add the put 50 00:03:52,150 --> 00:03:52,690 item command. 51 00:03:52,690 --> 00:03:58,230 So please copy or import with clicking this button in our case. 52 00:03:58,240 --> 00:03:59,530 In my case it's not working. 53 00:03:59,530 --> 00:04:01,900 So that's why I have added manually. 54 00:04:03,640 --> 00:04:04,300 Okay. 55 00:04:04,300 --> 00:04:10,690 So make sure that you have edit put item command under the your client dynamo DB library import statement. 56 00:04:10,720 --> 00:04:17,800 If you go back to at the end of the method, you can see that the put item command is located in here. 57 00:04:17,830 --> 00:04:24,820 So if you go right click and go to definition, you can see the input parameters into the output item 58 00:04:24,850 --> 00:04:26,090 input object. 59 00:04:26,110 --> 00:04:31,390 We can see the table name, item, expected return modus and so on. 60 00:04:31,690 --> 00:04:34,480 Okay, so please go back to our method. 61 00:04:34,510 --> 00:04:36,790 Okay, let's explain the method. 62 00:04:37,150 --> 00:04:39,600 As you can see in here, we have a try case below. 63 00:04:39,640 --> 00:04:46,060 And in the first line of code we basically log the operation, which means we are in the create product 64 00:04:46,060 --> 00:04:49,030 method and also logging the incoming event JSON object. 65 00:04:49,120 --> 00:04:52,290 And after that, the important part is in here. 66 00:04:52,300 --> 00:04:57,310 So we basically pass even that body information and get the request body. 67 00:04:57,340 --> 00:05:04,120 So what is included in these event body information if you go to the our. 68 00:05:05,820 --> 00:05:06,680 Even to object. 69 00:05:06,690 --> 00:05:11,620 Let me close these files and go to the post JSON file under the events. 70 00:05:11,640 --> 00:05:15,180 You can see that in the body of this event. 71 00:05:15,360 --> 00:05:16,620 Some object here. 72 00:05:16,620 --> 00:05:23,700 We have a JSON object that is the item of the product table, including the ID as a passing key. 73 00:05:23,700 --> 00:05:28,230 A name and price is attributes of this product dynamo DB table. 74 00:05:28,230 --> 00:05:34,710 So that's why the first thing we should pass this JSON in our code and after that we get this request 75 00:05:34,710 --> 00:05:42,000 body and paste this request body to the item of the parameters of put item command object. 76 00:05:42,000 --> 00:05:48,750 So it is required for the put item command and these are the properties as a table name and item an 77 00:05:48,750 --> 00:05:52,830 item comes from the JSON parts of the event body object. 78 00:05:53,040 --> 00:05:56,970 So as you can see that we are using in here marginal operation. 79 00:05:56,970 --> 00:06:01,800 If you don't use Marshall operation, we have to specify the data types. 80 00:06:01,830 --> 00:06:03,090 Let me show in here. 81 00:06:03,120 --> 00:06:08,430 This should be the structure of the number and the string will be in here. 82 00:06:08,430 --> 00:06:15,570 But when we are using the Marshall, we can pass the whole JSON object and this will be handled all 83 00:06:15,570 --> 00:06:16,740 operations for us. 84 00:06:16,740 --> 00:06:26,550 So that's why I'm removing these old style item definition and come here, we basically create a request 85 00:06:26,550 --> 00:06:34,590 body information and paste these JSON object as a dynamic DB item into parameters with using Marshall 86 00:06:34,590 --> 00:06:36,870 Utility Libraries. 87 00:06:37,200 --> 00:06:37,830 Okay. 88 00:06:37,830 --> 00:06:43,260 And also, as you know, that table name comes from the environment variables that we set this information 89 00:06:43,260 --> 00:06:49,470 when creating lambda function, we can go to configurations and set the table name or any environment 90 00:06:49,470 --> 00:06:50,730 variable in that place. 91 00:06:50,730 --> 00:06:56,520 So that's why we get these information from that and set the parameters of table name in here. 92 00:06:56,520 --> 00:07:03,840 So after we have prepared the parameters of to put item command, we basically use put item command 93 00:07:03,870 --> 00:07:07,860 in order to insert any item into Dynamo DB table. 94 00:07:07,950 --> 00:07:14,840 So this is important statement and this is again a variable request to send Dynamo DB with using input 95 00:07:14,850 --> 00:07:15,660 item command. 96 00:07:15,690 --> 00:07:21,690 This will return to create result of this operation success or fail. 97 00:07:21,720 --> 00:07:26,760 And we basically log this result and return back to resort to the function response. 98 00:07:26,760 --> 00:07:33,690 And there is one thing we should consider very importantly is you remember that we are parsing the request 99 00:07:33,690 --> 00:07:41,550 body and these body information is becomes an item, but this item should be include some attributes 100 00:07:41,550 --> 00:07:42,930 from the post operation. 101 00:07:42,930 --> 00:07:49,050 You can see the body information, but these JSON objects, the item object of the product should be 102 00:07:49,050 --> 00:07:52,440 include primary K, which means the partition K. 103 00:07:52,440 --> 00:07:58,350 So for that purpose, let me open the documentation and see that we are using PWD Item Command and this 104 00:07:58,350 --> 00:08:03,840 command basically creates a new item or replace an old item with any item. 105 00:08:03,840 --> 00:08:10,190 So if we check the product dynamo, we definition, we have a product table and the ID is a partition 106 00:08:10,200 --> 00:08:13,800 K so you can come here and go to Dynamo DB. 107 00:08:14,250 --> 00:08:21,300 You can see that we have a product table and partition and primary key is ID information. 108 00:08:21,300 --> 00:08:27,780 So that means according to this point, put item command, if you send a same ID in several times, 109 00:08:27,780 --> 00:08:33,600 this will be updated and existing item and not create any item and not return any exception. 110 00:08:33,600 --> 00:08:36,540 So this is the important thing that you should know. 111 00:08:36,540 --> 00:08:42,840 Understand which command you are using and understand what is doing in this command. 112 00:08:42,870 --> 00:08:44,340 This is very important. 113 00:08:44,340 --> 00:08:51,540 So since we send the ID information, for example, in, let me open the OR post JSON. 114 00:08:51,540 --> 00:08:54,720 So basically we are sending this kind of JSON object, right? 115 00:08:54,720 --> 00:09:01,260 So since we send the ID information and use the put item command, this will replace our existing record. 116 00:09:01,410 --> 00:09:04,770 And we don't want to do this in order to solve this issue. 117 00:09:04,800 --> 00:09:11,250 We should not send the ID partition key information and partition key should be generated automatically 118 00:09:11,250 --> 00:09:13,560 with using UUID libraries. 119 00:09:13,560 --> 00:09:21,270 So that means if you come here and if you send the same ID information as a JSON body, this will be 120 00:09:21,270 --> 00:09:24,810 replaced our code and we don't want to do this kind of operation. 121 00:09:24,810 --> 00:09:32,310 We only would like to use a name information or create a new item on our table and we don't want to 122 00:09:32,340 --> 00:09:38,970 update existing ID record in order to avoid these kind of issues, we should generate these IDs, right? 123 00:09:39,950 --> 00:09:43,340 Generate with your ID library. 124 00:09:43,640 --> 00:09:50,120 So that means in the next video we will generate these ID information when creating any product on our 125 00:09:50,120 --> 00:09:51,050 dynamic DB. 126 00:09:51,080 --> 00:09:58,490 To avoid the overwrite operation, we use the generating the ID with you ID library. 127 00:09:59,270 --> 00:10:05,210 So in order to solve this issue, we should not send the ID information in the body operation. 128 00:10:05,210 --> 00:10:11,090 We will solve this issue with generating the ID with using you ID libraries. 129 00:10:11,090 --> 00:10:17,780 So in the next video we will see how we can use your ID library in order to generate product table partition 130 00:10:17,780 --> 00:10:18,560 k column.