WEBVTT 00:00.770 --> 00:07.010 Now, if you remember this diagram from the beginning of the project, one of the things related to 00:07.040 --> 00:11.030 database that I wanted us to create is a model class. 00:11.030 --> 00:18.110 This would abstract not the whole database, but instead it would relate to one single table. 00:18.140 --> 00:25.280 So you can create a model that will represent the post, the comment and the user. 00:25.310 --> 00:32.450 The reason for that is typically you might have to write some more complex queries and that's fine. 00:32.450 --> 00:33.950 That's a separate problem. 00:33.980 --> 00:37.460 But a lot of those queries are super simple. 00:37.460 --> 00:46.640 You just fetch one individual record or you fetch all of them, or you just need to count the models, 00:46.640 --> 00:50.600 or you need to create a new record or update it. 00:50.600 --> 00:58.220 And for those cases, it would be super useful to have a generic model class that can do all of that 00:58.220 --> 01:06.340 without us Having to write the same queries over and over again for every single table that we have 01:06.340 --> 01:09.010 and we might have in the future. 01:09.010 --> 01:17.770 That's why in this video, we are going to create this base model class that all the future models that 01:17.770 --> 01:20.080 we're going to have will use. 01:21.640 --> 01:26.350 So our model class will heavily use this database class. 01:26.350 --> 01:30.310 It's going to get access to it through the container. 01:31.330 --> 01:33.130 Let me close the database for now. 01:33.130 --> 01:37.120 And inside the core let's create the model. 01:37.360 --> 01:38.350 PHP file. 01:38.650 --> 01:44.290 And this time I'm not gonna forget the core namespace. 01:45.520 --> 01:47.920 So this is our class model. 01:47.920 --> 01:51.280 And I think that this should be an abstract class. 01:51.280 --> 01:53.470 It should not exist on its own. 01:53.470 --> 01:55.960 It only needs to be extended. 01:57.310 --> 02:04.600 So we add a protected field that is static and it's a table name. 02:04.600 --> 02:11.350 So every model that extends this base model class would have to define the table name. 02:11.350 --> 02:15.160 That can be posts, users or comments in our case. 02:16.090 --> 02:23.650 So I think that it would make a lot of sense if I would begin this by defining the names of methods 02:23.650 --> 02:26.020 that this model would have. 02:26.890 --> 02:32.350 So let me start with the public ones and they are static. 02:32.710 --> 02:41.410 So we're going to have an all method which will just return all instances of this model. 02:41.650 --> 02:44.470 And that's always an array. 02:44.500 --> 02:46.990 Now I'm not going to implement it right away. 02:46.990 --> 02:53.350 I'm just defining those methods methods first so we can see what's the generic idea. 02:53.380 --> 02:56.230 Then we have a find method. 02:56.230 --> 03:02.910 And this accepts an id I think it should be mixed because it can be a number. 03:02.940 --> 03:09.750 Sometimes we also might use strings as primary keys, so we shouldn't be limited here. 03:10.500 --> 03:15.330 And this should return an instance of our model class. 03:15.480 --> 03:22.410 So I will define this as static or null if the model can't be found. 03:22.410 --> 03:29.100 But then we should also have some shortcut methods to quickly create a new model. 03:33.240 --> 03:35.580 So this would just be called create. 03:36.000 --> 03:42.060 And this is going to accept the array with the data with all the fields. 03:42.060 --> 03:46.470 And this should create an instance of this model. 03:46.470 --> 03:49.020 I'm using static as the return type. 03:49.020 --> 03:56.550 Because once we extend this base model class, this return type would have the proper class type. 03:56.550 --> 04:03.900 So it would be a specific model like post comment or a user, not the model class. 04:05.550 --> 04:10.830 So why won't we just go ahead and implement those methods starting with all? 04:10.920 --> 04:13.680 Now we need to get the database first. 04:13.710 --> 04:19.620 For that we're going to be using the app class, our dependency injection container. 04:20.520 --> 04:27.300 Now here is a thing in PHP, if you have classes at the same level of the namespace, you don't need 04:27.300 --> 04:34.290 to add use statements for them and model and app seem to be at the same level. 04:34.320 --> 04:41.910 That's why I can just do app get and I get the database. 04:41.910 --> 04:48.660 Now remember I told you that we won't have the suggestions with the methods of the database class, 04:48.690 --> 04:51.840 but we are going to fix that later. 04:51.840 --> 04:58.370 In the meantime, let's have the results by doing the DB query. 05:00.230 --> 05:10.400 And we're just going to select all columns from the specific table which is just static table. 05:10.970 --> 05:12.050 That's everything. 05:12.080 --> 05:14.750 This method is this simple. 05:14.750 --> 05:19.970 And we're going to do fetch all because this returns a statement. 05:20.210 --> 05:29.240 And then we're just going to say that using PDL we want to fetch that as an associative array. 05:30.050 --> 05:37.550 Let's make sure I got this PDL object imported because this one actually has to be imported. 05:38.390 --> 05:44.480 Now the problem with this is that we're going to get an array an array of arrays. 05:44.480 --> 05:47.420 So this would be a multi-dimensional array. 05:47.420 --> 05:53.930 And what I'd like instead is to have an array of objects. 05:53.930 --> 06:02.590 So every single time we use the model to fetch the data we wanted returned us this model class. 06:02.590 --> 06:04.870 So as a post or as a comment. 06:05.440 --> 06:12.520 Now this is not easily doable if we want to fetch multiple records. 06:12.520 --> 06:18.490 That's why we would need a helper method that we're going to make it protected. 06:18.700 --> 06:26.830 And I will call that create from array. 06:27.940 --> 06:34.480 And this receives an array data and returns static. 06:34.480 --> 06:37.300 So the current model we are working on. 06:38.530 --> 06:45.130 So we're going to be creating a new instance of static which means the current class whatever that is 06:45.130 --> 06:47.200 post comment user. 06:47.230 --> 06:50.620 Because this class always has to be extended. 06:51.610 --> 07:01.930 Then we're gonna go over the data which should be keys and values because that's an associative array. 07:02.380 --> 07:07.330 And then if the property is defined on the model. 07:07.570 --> 07:13.840 So there is this property exists function in PHP which accepts object or class. 07:14.290 --> 07:19.960 Well we have an object and the name of the property is the key. 07:20.230 --> 07:27.700 So if that's the case, if this property is defined I seem to forget to ask you what here. 07:27.700 --> 07:34.390 So if it is defined we just do model key. 07:34.420 --> 07:39.760 So we dynamically calculate the property name by using a variable. 07:40.120 --> 07:42.730 And we set that to value. 07:44.410 --> 07:47.290 And then we return a model. 07:47.320 --> 07:58.350 Now in the model PHP versions since PHP 8.2 I think you shouldn't really set the properties on classes 07:58.350 --> 07:59.340 dynamically. 07:59.340 --> 08:01.590 That was previously a feature of PHP. 08:01.740 --> 08:10.350 Now, if you use an object of a specific class, you have to define the properties explicitly. 08:10.350 --> 08:12.000 So this is deprecated. 08:12.000 --> 08:19.530 And if you would try to set the properties dynamically without them being explicitly defined on the 08:19.530 --> 08:23.400 class, this would cause a notice or warning. 08:23.400 --> 08:25.710 We're going to see that later on. 08:25.740 --> 08:35.610 Anyway, we need to use this method to now convert an array of arrays into an array of objects. 08:36.390 --> 08:44.100 So now we would like every single record of data that sits inside this results array to be converted 08:44.100 --> 08:45.330 to an object. 08:45.330 --> 08:52.200 And for that we're going to use our newly created create from array method. 08:53.400 --> 08:57.380 Now to convert every single record that is returned. 08:57.380 --> 09:06.200 Because this is results variable with multiple possible results, we can use an array map. 09:06.230 --> 09:08.360 This can be done different ways. 09:08.360 --> 09:15.170 We can also use a for each loop, but I think the array map makes the most sense. 09:15.200 --> 09:17.360 Let me start with the second argument. 09:17.360 --> 09:20.180 This would be the results array. 09:21.020 --> 09:25.010 And now going back to the first argument, this needs to be a callback. 09:25.040 --> 09:27.380 But here we don't have a function. 09:27.380 --> 09:31.490 We have a class method that is static. 09:32.090 --> 09:40.340 To parse it, we're going to use an array where the first element of the array is the name of the class. 09:40.370 --> 09:48.740 Now, to get the name of the current class, we can use the static keyword and it should have a class 09:48.740 --> 09:49.670 constant. 09:49.700 --> 09:57.890 Every class has this special constant that will give you the full class name, including the namespace, 09:58.550 --> 09:59.870 and after a comma. 09:59.900 --> 10:02.150 The second element is the method name. 10:02.690 --> 10:05.960 In our case, that's create from array. 10:06.290 --> 10:13.520 Now this is actually an important thing to remember that every single time you need to pass a method 10:13.520 --> 10:18.530 of a class, like in this case that's a class method. 10:18.560 --> 10:27.260 Or if you would need to pass a method of an object, then this first element of the array can be a variable 10:27.260 --> 10:28.610 with an object. 10:28.790 --> 10:38.390 And that's the way you can use if you pass a callback that is just a part of a class or a method, not 10:38.390 --> 10:40.040 a simple function. 10:41.420 --> 10:45.410 Okay, next up, let me build this find method. 10:45.410 --> 10:49.100 It would be pretty similar to the all method. 10:49.880 --> 10:52.790 There are of course some slight differences. 10:53.050 --> 10:57.970 That's why I'm just gonna copy and paste some of the code. 10:58.180 --> 11:02.860 So in the find method, we expect just a single result. 11:03.130 --> 11:07.300 We can still use this database query method. 11:08.020 --> 11:12.160 We're gonna select a record from the same table. 11:12.160 --> 11:13.360 This stays the same. 11:13.360 --> 11:16.390 But here we need some filters. 11:16.420 --> 11:21.700 That's why we are adding a Where clause to specify some conditions. 11:22.210 --> 11:28.150 In our case this is an ID and we're going to use prepared statements. 11:28.150 --> 11:34.660 That's why I'm going to add a question mark here for the positioned query arguments. 11:34.660 --> 11:36.910 And then I can pass the ID. 11:37.180 --> 11:44.350 So when you are using those question marks in prepared statements the order of them matters. 11:44.350 --> 11:48.880 Because then you just need to pass the parameters that you want to pass there. 11:48.910 --> 11:51.340 In the same order. 11:51.640 --> 11:57.670 So in this case, we will be using just a fetch method to get one record. 11:58.000 --> 12:06.040 Well, we can also use PDO fetch as sock to fetch the data as an associative array. 12:06.070 --> 12:07.900 Just a single record. 12:07.900 --> 12:14.350 And then we return the result depending on whether the result is not null. 12:14.830 --> 12:23.110 So if it is not null, we're going to use the static create from array method on the result array. 12:23.140 --> 12:25.240 Otherwise we return null. 12:26.650 --> 12:33.940 Now the last thing remaining so far is this create static method that will just insert one record into 12:33.940 --> 12:34.930 the database. 12:34.960 --> 12:43.030 Now this might take some time to implement and also explain, because we need to go in more details 12:43.030 --> 12:46.330 into how the insert SQL query works. 12:46.330 --> 12:52.300 That's why I think we should take a short break right now and just go back to it in the next video.