WEBVTT 00:00.740 --> 00:01.070 All right. 00:01.100 --> 00:07.970 Next up, let's go ahead and modify our abstract schema, which right now is representing the abstract 00:07.970 --> 00:10.040 document in the mongoose world. 00:10.070 --> 00:12.440 Let's go ahead and start off by renaming this. 00:12.440 --> 00:19.850 So instead of abstract schema, we're going to create an abstract entity, which is the same thing as 00:19.850 --> 00:29.440 a document or schema in Mongoose so we can remove the schema decorator and the ID property. 00:29.450 --> 00:36.320 Let's change the name to abstract entity and remove these imports to mongoose. 00:36.350 --> 00:42.590 Now I want to add just one property called ID of type number, which is going to represent the primary 00:42.590 --> 00:45.680 key of all our entities in our application. 00:45.680 --> 00:51.770 So since this is a primary key, this is going to be a unique value that automatically increments each 00:51.770 --> 00:55.220 time a new entity is created in that given table. 00:55.220 --> 01:01.670 So let's go ahead and mark this as the primary generated column to indicate this. 01:01.710 --> 01:08.190 So in type ORM, to actually save these entities to the database, we're going to actually be instantiating 01:08.190 --> 01:14.700 new instances of this class, the abstract entity which we didn't have to do in mongoose. 01:14.700 --> 01:21.720 So in order to make this easy, we'll go ahead and supply a common constructor that we can use when 01:21.720 --> 01:27.480 we want to create a new entity out of a subset of properties that exist on that entity. 01:27.480 --> 01:33.600 So in the constructor we'll take in the partial entity which will be of type partial, and then we'll 01:33.600 --> 01:35.250 take in a T here. 01:35.250 --> 01:41.970 So the abstract entity also takes in that T, and then inside the constructor we'll call object, dot 01:41.970 --> 01:46.140 assign and reference this and then the entity. 01:46.410 --> 01:53.760 So what this is going to do is it's going to take all of the properties on this partial entity being 01:53.760 --> 02:00.720 provided to the constructor and assign them to the abstract entity, which just means that all the properties 02:00.720 --> 02:06.780 that get passed in the constructor will be copied over to the newly created instance of this class, 02:06.780 --> 02:10.080 making it very easy to create new entities. 02:10.740 --> 02:15.210 We will see how this works in practice soon when we start saving entities. 02:15.420 --> 02:21.450 So now that we've defined the abstract entity, let's go back to our abstract repository where of course 02:21.450 --> 02:26.430 we can see it's having an issue because the abstract document no longer exists. 02:26.460 --> 02:33.090 Let's refactor this abstract repository to move away from mongoose and instead work with type ORM. 02:33.090 --> 02:38.430 So all of the repositories in our microservices will get this functionality. 02:38.580 --> 02:43.050 Okay, so to start, let's remove this import to the abstract document. 02:43.050 --> 02:50.880 And now in the abstract repository, instead of extending the abstract document here, let's change 02:50.880 --> 03:02.480 this to be t extends abstract entity which we've just created and then pass in the t to this abstract 03:02.480 --> 03:03.290 entity. 03:07.600 --> 03:11.500 So this T here is going to be the entity that the. 03:13.180 --> 03:20.230 Subclass of the abstract repository will be passing in, which will be extending the abstract entity. 03:20.560 --> 03:22.930 We're going to keep the logger the same. 03:22.930 --> 03:28.210 And now in the constructor, let's change this out to no longer take in a model. 03:28.420 --> 03:35.410 Instead, we're going to go ahead and inject two separate dependencies to allow us to interact with 03:35.410 --> 03:36.850 the SQL database. 03:37.090 --> 03:45.130 The first is going to be private read only entity repository, and this is going to be of type repository 03:45.130 --> 03:50.500 from type ORM, and we can pass in the T to get some type information around it. 03:50.500 --> 03:58.030 So this entity repository is what we're going to be using to find different entities in the database 03:58.030 --> 04:03.550 and get some type information around our queries, which is very similar to the model that we worked 04:03.550 --> 04:05.140 with with Mongoose. 04:05.320 --> 04:12.830 So additionally, we're also going to inject a private read only entity manager of type entity manager, 04:12.830 --> 04:20.960 and the entity manager is going to allow us to save entities in our database using instances of the 04:20.960 --> 04:22.460 entities that we've created. 04:22.460 --> 04:26.780 So let's go ahead and get started with the async create method. 04:27.080 --> 04:35.180 So now instead of taking in a document, we're going to be taking in an entity of type T, and we're 04:35.180 --> 04:37.700 going to return a promise of type T. 04:37.730 --> 04:43.750 Now we can remove everything in the create method and all we're going to do is simply return this dot 04:43.790 --> 04:46.640 entity, manager, dot save. 04:46.910 --> 04:51.290 And you can see here that this will save all of the given entities in the database. 04:51.320 --> 04:55.760 If they don't exist, it will insert, otherwise it will update these entities. 04:55.760 --> 05:00.770 So in a sense this will be doing an upsert for all the entities that are passed in. 05:00.770 --> 05:08.560 So we'll pass in the entity and now we can create new entities in our database. 05:08.570 --> 05:11.100 Let's move on to the find one method. 05:11.120 --> 05:14.690 So let's get rid of the filter query as a parameter. 05:14.690 --> 05:20.120 And our first parameter is going to be called where and this is going to be our where clause or our 05:20.120 --> 05:20.830 query. 05:20.840 --> 05:28.460 So this is going to be of type find options where from type ORM and we'll pass in the T as well. 05:28.460 --> 05:37.490 So let's replace this line here and instead of getting a document we'll call const entity is equal to 05:37.490 --> 05:42.560 await this dot entity repository dot find one. 05:42.920 --> 05:49.700 And here we pass in an options object where we pass in that where clause which is going to allow us 05:49.700 --> 05:54.050 to match a simple condition that's applied to match entities. 05:54.230 --> 06:00.590 So now that we have this entity pulled back from the database, let's go ahead and check to see if it 06:00.590 --> 06:01.430 exists. 06:01.430 --> 06:10.220 So if the entity doesn't exist, we will say entity not found with where, and then we can provide the 06:10.220 --> 06:11.360 where clause. 06:11.540 --> 06:18.940 Let's also go ahead and change the promise Ms. of t document out with just a promise of type T And then 06:18.940 --> 06:23.380 lastly, we're going to go ahead and return the entity instead of the document. 06:23.510 --> 06:28.000 Also go ahead and change the not found exception to be an entity not found. 06:28.210 --> 06:30.430 So now we have a find one. 06:30.430 --> 06:33.550 Let's move on to find one and update. 06:34.030 --> 06:35.980 This is going to look quite similar. 06:35.980 --> 06:41.980 We'll take in the where clause which is find options where. 06:43.170 --> 06:49.590 And then for the update parameter, we'll change this to partial entity, which is exactly what it's 06:49.590 --> 06:50.010 going to be. 06:50.010 --> 06:54.420 It's going to be a partial subset of our entity, which we want to update. 06:54.420 --> 07:02.540 So this type is going to be called query deep partial entity and pass in our type of T. 07:03.840 --> 07:09.510 So essentially this is going to be a subset of properties that exist on our entity that we want to be 07:09.510 --> 07:10.470 updating. 07:10.980 --> 07:18.900 And so we'll go ahead and change our update expression to a new const called update result. 07:19.740 --> 07:27.390 And we'll set this equal to await this dot entity repository dot update. 07:28.080 --> 07:34.950 And here we'll pass in our where clause as the criteria to find the entity to update and then we'll 07:34.950 --> 07:36.780 pass in the partial entity. 07:37.080 --> 07:42.780 So next, let's check to see if the update result Dot affected, which is going to be the number of 07:42.780 --> 07:47.010 affected documents by the update statement is zero. 07:47.010 --> 07:55.170 So if this is zero, which is what this expression will check for, then we want to warn that the entity 07:55.200 --> 08:00.300 was not found with where and pass in our where clause. 08:00.330 --> 08:04.070 We'll also change the exception to entity not found. 08:04.090 --> 08:11.080 Then in order to get the most up to date entity, we'll return this dot find one which is the method 08:11.080 --> 08:16.780 in this abstract repository and we'll pass in the same where clause to get the most up to date version 08:16.780 --> 08:19.790 of this entity after the update was applied. 08:19.810 --> 08:25.840 So lastly, these two remaining methods find and find one and delete are going to be very simple. 08:26.020 --> 08:33.550 Async find is going to take in a different parameter here that we'll call where as we've done before, 08:33.580 --> 08:42.880 this will be find options where as we are used to, we pass in the type of T and then we're simply going 08:42.880 --> 08:52.960 to return this dot entity repository dot find by and pass in the where clause which is going to allow 08:52.960 --> 08:57.730 us to find multiple entities that all match this where clause. 08:59.010 --> 09:06.630 And finally, for find one and delete, we will have the where clause which is going to be find options 09:06.630 --> 09:16.170 where of type T and instead of returning the deleted result we are going to call await this dot entity 09:16.170 --> 09:21.060 repository, dot delete and pass in the where clause.