WEBVTT 00:01.510 --> 00:02.140 Okay. 00:02.140 --> 00:06.850 In this video, we will create our first models in our application. 00:06.850 --> 00:12.010 So let's open a models.py here and we can create models here. 00:12.220 --> 00:17.020 As you remember, the way to create a model is class and the name of the model. 00:17.020 --> 00:19.780 What we what models do we need in our application? 00:19.780 --> 00:27.580 Basically, based on our requirements, we will need to have a list of movies and also will rate that 00:27.580 --> 00:27.940 movie. 00:27.940 --> 00:29.650 So we will need two models. 00:29.650 --> 00:31.090 First will be movie. 00:32.990 --> 00:34.640 So we can do models. 00:37.730 --> 00:42.920 Model like that and then we can have a title. 00:44.880 --> 00:46.810 This field will be models. 00:48.970 --> 00:50.010 Char Field. 00:50.940 --> 00:53.340 And let's say max length. 00:53.370 --> 00:57.330 I think for a movie title will be 32 will be more than enough. 00:57.330 --> 00:59.430 And then we can have a description. 01:01.920 --> 01:03.660 And we can do models. 01:03.900 --> 01:04.980 Models. 01:06.920 --> 01:12.020 And on this one we can do text field because that will be much larger. 01:12.020 --> 01:13.850 So we can do max length. 01:13.850 --> 01:21.140 Let's say we can have a 360 character and just an arbitrary number here. 01:21.140 --> 01:24.830 So what we have is we have our movie here. 01:24.830 --> 01:32.060 We also need to create a new class, new model for our rating like that. 01:32.060 --> 01:36.650 And in the same way so we models model, import it. 01:36.650 --> 01:40.670 And here what we can do is we will have few things. 01:40.670 --> 01:43.820 First, we need to have a reference to our movie. 01:43.820 --> 01:53.630 So our movie will be models foreign key, and then we'll refer our movie here. 01:55.190 --> 01:59.080 So we will have a reference from the rating to movies. 01:59.080 --> 02:03.650 So whatever we'll create a rating, we'll need to create a for specific movie. 02:04.160 --> 02:10.550 Another I can actually duplicate this and I will have a reference to user. 02:10.580 --> 02:17.810 The reason why I'm having this is I will kind of explain you and show you that in a second. 02:17.810 --> 02:22.280 And once we will start to test our API, it will make more sense. 02:22.280 --> 02:31.490 But what we want to have is if we create a rating for our movie, we will have a reference to the movie. 02:31.490 --> 02:38.900 So this rating will be for specific movie, but also we'll need to also tell what user created that 02:39.320 --> 02:40.070 rating. 02:40.070 --> 02:49.640 So basically if we have a login user, that user will be sent with the request and we need to store 02:49.640 --> 02:55.860 that user so user won't be able to create million reference ratings for one movie. 02:55.860 --> 02:59.430 So one rating per movie per user. 02:59.430 --> 03:07.110 So this in this way we need to reference the user, but a user is not available here, so we need to 03:07.110 --> 03:07.920 import it. 03:07.920 --> 03:14.700 As you can see here, the class a user doesn't exist, but we can import it actually from Django. 03:14.700 --> 03:17.460 So from Django. 03:19.680 --> 03:20.760 Contrib. 03:22.790 --> 03:27.230 Out models import user. 03:27.530 --> 03:35.000 So we have our user imported from the Django contrib authentication models that's built in model inside 03:35.030 --> 03:35.480 Django. 03:35.480 --> 03:43.040 As we can go here, you can see users here, that's a user built in in authentication. 03:43.040 --> 03:49.940 And what we are doing here is we import that user from, from Django itself and now we have two references. 03:49.940 --> 03:53.390 So we have movie and we also have that user. 03:53.390 --> 04:03.430 What we also need to do is do on delete and then we'll do models, cascades. 04:03.560 --> 04:04.550 Cascade. 04:05.240 --> 04:07.400 Cascade like that. 04:07.700 --> 04:09.590 And that will do it for both. 04:09.830 --> 04:19.340 So basically what I'm saying here is if we remove that movie, we also need to remove that rating. 04:19.340 --> 04:28.320 So if we remove that model, then we will cascade it and remove the rating because if we will have a 04:28.320 --> 04:34.410 rating with that movie and the movie will be removed from our database, it will break our application, 04:34.410 --> 04:35.670 it will break the logic. 04:35.670 --> 04:41.370 So whatever this model will be removed, we cascade it and remove the rating as well. 04:41.790 --> 04:49.380 So we have two references now, but it will be good to also have some kind of rating so we can call 04:49.380 --> 04:50.400 it stars. 04:51.540 --> 04:58.650 So we creating our rating, we will tell what is the number of stars. 04:58.650 --> 05:02.400 We would like to give that to our model. 05:02.400 --> 05:09.750 So what we can do is we can use models and then we can do integer field. 05:09.750 --> 05:13.920 So Integer Field will store the integer for us. 05:13.920 --> 05:22.050 But how can we actually tell Django that we would like to have only from 1 to 5 stars? 05:22.050 --> 05:23.760 We can use validators. 05:23.760 --> 05:31.050 I haven't talked about the validator validators yet, but it is something available in the Django and 05:31.050 --> 05:33.840 we can import that and use it in the field. 05:33.840 --> 05:34.920 So from. 05:36.850 --> 05:41.110 Django core validators. 05:41.710 --> 05:44.180 We can import max length. 05:44.710 --> 05:51.670 Max value validator and also we can import minimum value validator. 05:51.670 --> 06:02.230 So we have to validate those here and inside here we can actually use the validators in the field and 06:02.230 --> 06:09.520 we can specify what will be the minimum value for this integer and the maximum value for this integer. 06:09.520 --> 06:14.710 So what we need to do is we need to type validators here and that's going to be an array. 06:14.710 --> 06:18.310 So we do square brackets here and then we can decide it. 06:18.310 --> 06:21.490 So minimum valid value validator. 06:21.490 --> 06:27.730 And then we we do parentheses and then we can decide a minimum validator is one. 06:27.730 --> 06:37.190 So I do comma here and then I will do max value validator here inside that square brackets and then 06:37.190 --> 06:40.160 I can decide this max value will be five. 06:40.190 --> 06:47.300 So basically we are taking that stars it's an integer field so the whole number and then validators 06:47.300 --> 06:50.750 will use minimum value one and then max value five. 06:50.780 --> 06:55.040 So we can only accept values one, two, three, four and five. 06:55.070 --> 07:02.780 So that will be a very good for our stars because we don't want to have a user to pass any value he 07:02.780 --> 07:03.950 likes in the stars. 07:03.950 --> 07:08.390 So we'll put it concise and it will be very useful. 07:09.110 --> 07:20.480 Also, another thing that I haven't talked about it yet is unique together, so we know how to do unique 07:20.480 --> 07:25.310 things like we can decide that this field will be unique or this field will be unique. 07:25.310 --> 07:29.210 But I haven't talk yet about unique together. 07:29.210 --> 07:38.120 If we do class meta like this, what we can decide for this rating is we can decide. 07:45.640 --> 07:47.170 On unique together. 07:47.290 --> 07:55.660 We need to do brackets like this and inside another I will do our user. 07:59.860 --> 08:01.390 And movie. 08:02.290 --> 08:08.900 And also I can do index together in the same way. 08:08.920 --> 08:18.040 So basically what I'm saying here that if you create a rating, the only accepted values will be if 08:18.040 --> 08:22.360 the user and movie won't be already in our database. 08:22.360 --> 08:28.450 So let's say we have one movie and I will go to the testing later on and I will show you that on the 08:28.450 --> 08:30.300 example how we've done this. 08:30.310 --> 08:39.970 So basically what we are saying is if we have already rating for a specific movie by one user and if 08:39.970 --> 08:47.320 you would like to create a new rating for the same movie with the same user, it will be rejected because 08:47.320 --> 08:49.690 we have that unique together here. 08:49.870 --> 08:53.650 And also we do index together in the same way. 08:53.650 --> 09:05.480 So that's a setup for this model that will help us to do not accept any values that won't be acceptable 09:05.480 --> 09:06.170 for us. 09:06.170 --> 09:13.070 So we want to design this in a way that will work and it will be bulletproof and this is the way to 09:13.070 --> 09:13.460 do it. 09:13.460 --> 09:15.800 So I will save it now. 09:15.800 --> 09:19.970 And you can see here we have two classes, two, two models. 09:19.970 --> 09:26.300 Now what do we need to do is we need to create migrations and we need to apply it in our database. 09:26.300 --> 09:27.560 So let's do it now. 09:27.560 --> 09:30.290 So I will go Python. 09:32.510 --> 09:35.750 Manage.py make migrations. 09:39.820 --> 09:41.400 Supposed to be Python. 09:46.030 --> 09:47.740 And another typo. 09:49.150 --> 09:50.920 Manage.py make migrations. 09:50.920 --> 09:56.590 And you can see here two models has been created movie and rating. 09:56.590 --> 10:05.110 So what we need to do is we need to migrate it now, migrate like this and that's been created. 10:05.110 --> 10:11.080 So I will go to admin and I can register these two models here. 10:11.080 --> 10:13.240 So we go admin. 10:14.110 --> 10:16.660 Site register. 10:19.440 --> 10:26.820 And then model is one is movie and I will duplicate it and another one is rating. 10:27.060 --> 10:29.790 We also need to import it. 10:29.790 --> 10:30.870 So from. 10:32.200 --> 10:39.550 Models import movie and writing like that. 10:39.550 --> 10:41.650 So we have that done. 10:41.650 --> 10:50.050 And then if I go here and I will refresh it so it cannot be reached, probably we don't have our server 10:50.050 --> 10:51.640 running, so I go run. 10:52.840 --> 10:53.920 Click run here. 10:56.190 --> 10:58.830 Coming back here and then we'll refresh it. 10:59.460 --> 11:03.210 And you can see here movies and ratings are here. 11:03.210 --> 11:09.750 I can click here and if I will add new movie, it is available title and description. 11:09.750 --> 11:16.500 If I go back to API and then ratings, if I will try to add, we have movie at the moment we don't have 11:16.500 --> 11:23.130 any and then we have users, we have one user in our database and then we can do a number of stars. 11:23.130 --> 11:32.190 So if I will pick here, actually this, this field has no validation, but the Django will refuse it. 11:32.190 --> 11:38.220 If I will try to pass something different, then our validation there. 11:38.760 --> 11:41.190 So we have basic models set up. 11:41.190 --> 11:46.440 We haven't do anything with Serializers yet and we haven't done anything with views. 11:46.440 --> 11:52.770 So we'll focus on that in the next video and I will start testing our API. 11:52.800 --> 12:00.550 At the moment we have everything configured so we could add it, our models, our records in database 12:00.550 --> 12:08.560 in this admin section, but our goal is to use the API and return the Json. 12:08.560 --> 12:15.940 So we will try to debug it and make it work with our Json using the postman.