1 00:00:00,450 --> 00:00:01,320 ‫We'll come back. 2 00:00:01,320 --> 00:00:07,160 ‫Now that we have everything set up, we can go ahead and create our first code here. 3 00:00:07,170 --> 00:00:11,670 ‫Well, we have some code, but it's not the magic that we were expecting. 4 00:00:11,670 --> 00:00:12,150 ‫Right? 5 00:00:12,150 --> 00:00:19,200 ‫So let's go ahead and create a method which will insert universities into our university table because 6 00:00:19,200 --> 00:00:23,550 ‫we have this table university and if we check out the data. 7 00:00:24,120 --> 00:00:29,310 ‫So open table definition, it's not the one, but open or show table data. 8 00:00:29,520 --> 00:00:31,500 ‫If we do that, we see that it's empty. 9 00:00:31,500 --> 00:00:36,420 ‫So we have no idea, no name yet, but we are going to change that with code. 10 00:00:36,420 --> 00:00:46,500 ‫So let's create a new method and it's going to be a public void, insert universities and this method 11 00:00:46,500 --> 00:00:48,900 ‫should simply insert universities. 12 00:00:49,050 --> 00:00:53,430 ‫Once we call that, it will add universities to our university table. 13 00:00:53,550 --> 00:01:00,660 ‫Now in here, what I'm going to do is I first of all, need a university. 14 00:01:00,690 --> 00:01:06,420 ‫And in order to use this university class, because we didn't create a university class. 15 00:01:06,420 --> 00:01:06,690 ‫Right. 16 00:01:06,690 --> 00:01:08,910 ‫And I want to use university objects. 17 00:01:08,910 --> 00:01:15,720 ‫I need to go ahead to my link to SQL data, classes, DB, HTML and drag university in here. 18 00:01:15,720 --> 00:01:21,870 ‫So from my tables I drag university in and now I can go ahead and use university in here. 19 00:01:21,870 --> 00:01:26,010 ‫So it will take a little while, but now you can see now it's green and now we can use it. 20 00:01:26,340 --> 00:01:29,280 ‫Now let's go ahead and create an object. 21 00:01:29,280 --> 00:01:33,330 ‫I'm going to call that Yale, which will be a new university. 22 00:01:33,960 --> 00:01:38,040 ‫And this Yale object should have a name. 23 00:01:38,040 --> 00:01:40,500 ‫And as you can see, Yale has a name. 24 00:01:40,500 --> 00:01:45,570 ‫And that's pretty cool because when we can access its ID, we can access its name so we can access all 25 00:01:45,570 --> 00:01:47,370 ‫of its properties that we have set up. 26 00:01:47,370 --> 00:01:52,170 ‫And when we set up those properties, well, we did that in our table. 27 00:01:52,170 --> 00:01:56,550 ‫So you can create objects of your table and that's pretty cool. 28 00:01:56,550 --> 00:02:04,590 ‫So you can simply use this link to SQL data classes, HTML, and drag your tables in here and it will 29 00:02:04,590 --> 00:02:05,760 ‫create classes for you. 30 00:02:05,760 --> 00:02:06,600 ‫And that's pretty cool. 31 00:02:06,600 --> 00:02:15,030 ‫So we can now use the name and I'm going to set that name to Yale like that. 32 00:02:15,780 --> 00:02:25,350 ‫Now, in order to insert Yale into my data table with this name, I need to go ahead and use the data 33 00:02:25,350 --> 00:02:27,420 ‫context that we have set up in the last video. 34 00:02:27,420 --> 00:02:37,410 ‫So this one link to the data context and here in universities, so there is a property called universities, 35 00:02:37,800 --> 00:02:43,170 ‫it contains this method here insert on submit. 36 00:02:43,290 --> 00:02:45,210 ‫And what do we want to insert? 37 00:02:45,210 --> 00:02:50,760 ‫Well, an entity of university and the entity that I want to enter is Yale. 38 00:02:51,870 --> 00:02:59,490 ‫So what I'm actually doing here is I'm entering data into my table of university. 39 00:02:59,610 --> 00:03:01,110 ‫So this code does that. 40 00:03:01,110 --> 00:03:02,730 ‫And that's pretty neat, isn't it? 41 00:03:02,730 --> 00:03:12,330 ‫So in order to submit those changes, I simply do something at that data context that submit changes 42 00:03:12,660 --> 00:03:13,350 ‫and that's it. 43 00:03:13,350 --> 00:03:18,360 ‫So now I submit those changes, meaning I submit this insert on submit. 44 00:03:18,360 --> 00:03:21,150 ‫So as you can see, it's only inserting once it's submitted. 45 00:03:21,150 --> 00:03:29,520 ‫And in this line here I'm submitting now, in order to display the university on my table, I need to 46 00:03:29,520 --> 00:03:40,260 ‫call my main data grid and set its item source to the data context thought universities. 47 00:03:42,060 --> 00:03:48,660 ‫All right, so if we check what that is, well, main data grid is in our XAML file. 48 00:03:48,660 --> 00:03:50,850 ‫Is this data grid currently? 49 00:03:50,850 --> 00:03:51,870 ‫It doesn't have any data. 50 00:03:51,870 --> 00:03:52,530 ‫It's pretty empty. 51 00:03:52,530 --> 00:03:52,920 ‫Right. 52 00:03:52,920 --> 00:03:59,550 ‫But it's this data grid where we set this name to main data grid and now we are setting its item source 53 00:03:59,550 --> 00:04:01,980 ‫to the data context university. 54 00:04:01,980 --> 00:04:09,270 ‫So it will show us all the universities that are inside of our database or inside of this table. 55 00:04:09,270 --> 00:04:14,010 ‫So I'm going to call this Insert University's method. 56 00:04:16,590 --> 00:04:18,150 ‫And run the code. 57 00:04:18,300 --> 00:04:23,100 ‫And if I do that, you see that we have this ID one and the name Yael in here. 58 00:04:23,430 --> 00:04:26,970 ‫So that's what our code does already. 59 00:04:27,300 --> 00:04:30,410 ‫So no SQL entries yet. 60 00:04:30,420 --> 00:04:35,550 ‫We didn't need to use, wear or put something into and so forth. 61 00:04:35,550 --> 00:04:38,480 ‫We did all of that with code and that's pretty easy. 62 00:04:38,490 --> 00:04:41,130 ‫So you you create an object of your. 63 00:04:41,160 --> 00:04:46,530 ‫Well, in this case, it's a table name and you add some values to it. 64 00:04:46,530 --> 00:04:51,690 ‫In our case is just the name and you insert that on submit and you submit those changes. 65 00:04:51,690 --> 00:04:57,630 ‫And of course, if you want to see something, you need to set the item source as this data context 66 00:04:57,630 --> 00:04:58,530 ‫universities. 67 00:04:58,530 --> 00:05:05,760 ‫So now as a little challenge, add another university into the table and run the app. 68 00:05:08,250 --> 00:05:09,240 ‫I hope you tried it. 69 00:05:09,240 --> 00:05:11,220 ‫So I'm going to create a new university. 70 00:05:11,220 --> 00:05:12,840 ‫University? 71 00:05:12,870 --> 00:05:19,980 ‫It's going to be Beijing Tech, which is a new university. 72 00:05:20,880 --> 00:05:23,700 ‫And now Beijing Tech needs a name. 73 00:05:23,700 --> 00:05:30,960 ‫So I'm going to set its name to something like beI Jing Tech. 74 00:05:32,850 --> 00:05:39,120 ‫And now of course I need to call Data Context University's Dot insert on submit. 75 00:05:39,120 --> 00:05:43,590 ‫And in this case it's Beijing Tech that I want to submit. 76 00:05:43,590 --> 00:05:48,540 ‫And as you can see, the submit changes is also or is only needed once and here. 77 00:05:48,540 --> 00:05:51,540 ‫This is not all on submit but on submit. 78 00:05:51,540 --> 00:05:58,020 ‫So this data context submit changes will be executed once we don't need to execute it after every single 79 00:05:58,020 --> 00:06:05,010 ‫one, but we only need to execute it when we are ready to submit all those changes that we have prepared. 80 00:06:05,280 --> 00:06:05,880 ‫All right. 81 00:06:05,880 --> 00:06:07,680 ‫So now let's run it again. 82 00:06:07,680 --> 00:06:10,170 ‫And we should see two entries in there. 83 00:06:10,680 --> 00:06:13,260 ‫And I hope you tried to do that. 84 00:06:13,290 --> 00:06:14,880 ‫And actually, we see three entries. 85 00:06:14,880 --> 00:06:15,300 ‫Wow. 86 00:06:15,300 --> 00:06:16,200 ‫Why is that? 87 00:06:16,200 --> 00:06:21,930 ‫And you might wonder, but well, we ran the code already and now we run it again. 88 00:06:21,930 --> 00:06:24,360 ‫So we add all the universities again. 89 00:06:24,360 --> 00:06:25,800 ‫So what is going on? 90 00:06:25,800 --> 00:06:28,980 ‫Well, that's pretty much what we intended. 91 00:06:28,980 --> 00:06:31,470 ‫Well, at least in our code. 92 00:06:31,470 --> 00:06:33,090 ‫So this is exactly what we do. 93 00:06:33,120 --> 00:06:34,290 ‫We add new stuff. 94 00:06:34,290 --> 00:06:39,420 ‫We don't say, okay, this is all the stuff that we want to have in our universities table. 95 00:06:39,420 --> 00:06:41,760 ‫But we say, okay, we add those two new lines. 96 00:06:41,760 --> 00:06:45,150 ‫So if we execute and run again. 97 00:06:46,660 --> 00:06:47,650 ‫Or close and execute. 98 00:06:47,650 --> 00:06:52,120 ‫Again, we see we have Yale, Yale, Beijing Tech, Yale, Beijing Tech. 99 00:06:52,120 --> 00:06:59,710 ‫And now in order to clean that up, in order to only have the entries that we have in here, only those 100 00:06:59,710 --> 00:07:02,350 ‫two we can do something like that. 101 00:07:02,350 --> 00:07:04,030 ‫Data context dot. 102 00:07:05,130 --> 00:07:17,940 ‫Execute command and here we we simply use SQL code delete from universe C T like that. 103 00:07:17,940 --> 00:07:22,260 ‫So here it's needed to be correctly written. 104 00:07:22,260 --> 00:07:24,510 ‫So delete from university. 105 00:07:24,510 --> 00:07:29,460 ‫So this way I simply delete all the entries and then I add them. 106 00:07:29,460 --> 00:07:31,350 ‫So now we should only have two entries in there. 107 00:07:31,350 --> 00:07:35,850 ‫So only Yale and Beijing, as you can see, Yale in Beijing. 108 00:07:35,850 --> 00:07:39,090 ‫But what didn't change, as you can see as well, is the ID. 109 00:07:39,120 --> 00:07:41,550 ‫So it's still going up, up, up. 110 00:07:41,550 --> 00:07:48,690 ‫All the entries that we had before were all deleted, but the ID didn't go back to its starting value. 111 00:07:48,900 --> 00:07:51,330 ‫So that's something that you need to keep in mind. 112 00:07:51,660 --> 00:07:52,050 ‫All right. 113 00:07:52,050 --> 00:07:55,170 ‫So now you know how to insert data in there. 114 00:07:55,170 --> 00:08:03,540 ‫So now a little challenge, insert students and yeah, of course you can try to do that, but it's going 115 00:08:03,540 --> 00:08:09,180 ‫to be a bit difficult, I'd say a bit too difficult for now and I'm going to show you. 116 00:08:09,300 --> 00:08:15,180 ‫So let's create a new method and I'm going to call that insert students. 117 00:08:16,260 --> 00:08:21,000 ‫So public void insert students. 118 00:08:26,210 --> 00:08:30,500 ‫Because what I want to use here is a lambda expression. 119 00:08:30,680 --> 00:08:37,630 ‫And we haven't used lambda that much yet or not at all, based on how far you've gone in the course. 120 00:08:37,640 --> 00:08:42,410 ‫So what I'm going to use is I'm going to use a university here as well. 121 00:08:42,410 --> 00:08:52,670 ‫So I'm going to create a Yale University, but I'm going to use data context, dot universities so this 122 00:08:52,670 --> 00:08:53,420 ‫property. 123 00:08:53,420 --> 00:08:59,300 ‫And then if I open that up, as you can see, there are many different methods available here and the 124 00:08:59,300 --> 00:09:01,940 ‫one that I want to use is called first. 125 00:09:01,940 --> 00:09:06,290 ‫And what first does is it returns the first element of a sequence. 126 00:09:06,440 --> 00:09:12,950 ‫So first is going to return a the first element of a sequence. 127 00:09:12,950 --> 00:09:18,290 ‫So what I can do here is I can run a lambda expression in here. 128 00:09:18,290 --> 00:09:28,100 ‫So what I'm going to do is I'm going to say N which stands for university, should give me a UN name 129 00:09:28,100 --> 00:09:31,640 ‫that equals Yale. 130 00:09:34,990 --> 00:09:40,450 ‫So this is a very, very short line and it does a lot of stuff. 131 00:09:40,450 --> 00:09:42,250 ‫So it's it's pretty extended. 132 00:09:42,250 --> 00:09:46,090 ‫So it's very similar to, let's say, this statement here I'm going to show you. 133 00:09:46,360 --> 00:09:48,610 ‫So let's say this statement here. 134 00:09:48,610 --> 00:09:55,720 ‫So if I had to write it in SQL, it would look like that from university in data context. 135 00:09:55,720 --> 00:10:02,290 ‫University where university is equal to lane a Yale select that specific university. 136 00:10:02,710 --> 00:10:03,040 ‫All right. 137 00:10:03,040 --> 00:10:06,880 ‫So from university in data context university, we know what that is. 138 00:10:06,880 --> 00:10:08,020 ‫That's for each loop. 139 00:10:08,020 --> 00:10:13,450 ‫Then we say where the university is equal to a specific name and then select the university. 140 00:10:13,450 --> 00:10:20,200 ‫But instead of doing that, we simply have this very short piece of code which does exactly the same 141 00:10:20,200 --> 00:10:20,710 ‫thing. 142 00:10:20,710 --> 00:10:26,860 ‫So it's going to return the university and it's going to check for the first entry in that sequence. 143 00:10:26,860 --> 00:10:27,670 ‫So it's check. 144 00:10:27,670 --> 00:10:34,300 ‫It's checking for the first entry that is called Yale, and it's going to store that in Yale because 145 00:10:34,300 --> 00:10:41,020 ‫the difference of that is what that will return us is a i enumerable right. 146 00:10:41,020 --> 00:10:43,660 ‫It's a collection that will be returned if we run that code. 147 00:10:43,660 --> 00:10:49,720 ‫But the cool thing is here with this line, it's not returning a collection, but it's returning an 148 00:10:49,720 --> 00:10:54,730 ‫actual object of university and we can use that further on. 149 00:10:54,730 --> 00:11:00,160 ‫So it's, it's mighty, it's pretty -- strong and very short code. 150 00:11:00,160 --> 00:11:05,830 ‫So if you want to know more about what's going on here, then you should check out Lambda Expressions. 151 00:11:05,830 --> 00:11:12,040 ‫But I'm just going to use it like that for now because it's well, lambda expressions are a lot more. 152 00:11:12,040 --> 00:11:16,930 ‫They can do so much more than just this specific line that we have here. 153 00:11:16,930 --> 00:11:20,680 ‫But I'm just going to use it like that for now. 154 00:11:21,190 --> 00:11:33,190 ‫So I'm going to do the same thing for the other university, which will be beI Jing Tech, and we search 155 00:11:33,190 --> 00:11:37,000 ‫for Beijing Tech like that. 156 00:11:37,780 --> 00:11:42,790 ‫So now we have two different universities, the Beijing one and the Yale one. 157 00:11:42,880 --> 00:11:51,040 ‫Now instead of adding students to the universities individually, I'm going to add a whole list of students. 158 00:11:51,040 --> 00:11:55,930 ‫So I'm going to create a whole list of students and put them into the correct university. 159 00:11:56,380 --> 00:12:02,350 ‫And in order to do so, I'm going to, first of all, shut down the server explorer. 160 00:12:02,350 --> 00:12:05,560 ‫So I have more space here and. 161 00:12:07,030 --> 00:12:18,850 ‫Now I'm going to create a list of student and I'm going to call that students is a new list of student. 162 00:12:19,780 --> 00:12:21,490 ‫So now it's complaining. 163 00:12:21,490 --> 00:12:23,260 ‫It doesn't know what student is. 164 00:12:23,710 --> 00:12:30,370 ‫So what we need to do is we need to drag the student in here from our server explorer. 165 00:12:30,370 --> 00:12:35,500 ‫So open up server explorer again and drag your student in here. 166 00:12:36,290 --> 00:12:37,390 ‫So there we are. 167 00:12:37,400 --> 00:12:39,320 ‫And as you can see, they are connected. 168 00:12:40,040 --> 00:12:44,090 ‫And they are connected by the University ID. 169 00:12:45,440 --> 00:12:51,110 ‫Now we can go back into our code behind and after a little while students should be recognized that 170 00:12:51,110 --> 00:12:51,470 ‫we are. 171 00:12:51,470 --> 00:12:56,260 ‫And now we can use student as a class or we can make objects out of it. 172 00:12:56,270 --> 00:12:57,260 ‫That's pretty cool. 173 00:12:57,260 --> 00:13:00,080 ‫So let's create a new entry. 174 00:13:00,080 --> 00:13:05,210 ‫So we're going to use the ADD method, which will add an element to the list called students. 175 00:13:05,210 --> 00:13:06,920 ‫And what do we want to add here? 176 00:13:06,920 --> 00:13:10,100 ‫Well, I'm going to add a new student object. 177 00:13:10,100 --> 00:13:15,170 ‫So I'm going to say, okay, give me this whole student object with certain information. 178 00:13:15,170 --> 00:13:26,480 ‫So, for example, with the name of Karla, the gender of female and the age. 179 00:13:26,480 --> 00:13:32,450 ‫Well, actually, we don't need the age, but we need the university ID and I'm going to say something 180 00:13:32,450 --> 00:13:36,200 ‫like Yale Dot ID. 181 00:13:38,000 --> 00:13:38,330 ‫All right. 182 00:13:38,330 --> 00:13:39,740 ‫So like that. 183 00:13:39,740 --> 00:13:40,310 ‫Just like that. 184 00:13:40,310 --> 00:13:48,560 ‫With this entry, I have added a student to my student's list and I could use the student's list to 185 00:13:48,650 --> 00:13:51,980 ‫add that to my data context in the same way that we have done here. 186 00:13:51,980 --> 00:13:53,180 ‫So insert on submit. 187 00:13:53,180 --> 00:13:54,980 ‫I can drag those students in. 188 00:13:54,980 --> 00:13:59,240 ‫It will add this whole list of all the students that I have in my list. 189 00:13:59,300 --> 00:13:59,900 ‫All right. 190 00:14:00,290 --> 00:14:02,360 ‫So that's pretty powerful and cool. 191 00:14:03,860 --> 00:14:11,270 ‫But now another cool thing is, instead of using the university ID, I can just hand over to university 192 00:14:11,270 --> 00:14:15,310 ‫itself so I can create a new student entry. 193 00:14:15,320 --> 00:14:20,240 ‫I'm going to say new student with the name of Tony 194 00:14:22,550 --> 00:14:25,970 ‫and the gender of male 195 00:14:28,760 --> 00:14:30,710 ‫then and then university. 196 00:14:30,710 --> 00:14:38,150 ‫And as you can see, there is a property called university and I can just say it should be the Beijing 197 00:14:38,510 --> 00:14:39,800 ‫or in this case the Yale. 198 00:14:39,800 --> 00:14:45,770 ‫So let's say Tony is in Yale and let's write it like that. 199 00:14:45,890 --> 00:14:49,250 ‫So Tony is in Yale and now I'm going to add some more students. 200 00:14:49,250 --> 00:14:54,320 ‫So as you can see in this case, we use this university ID, now we're using the university and both 201 00:14:54,320 --> 00:14:57,110 ‫are fine because they are connected to each other. 202 00:14:57,110 --> 00:15:02,630 ‫A university has a specific ID and we use them pretty much same thing here. 203 00:15:02,750 --> 00:15:04,460 ‫Now I'm going to add some more. 204 00:15:04,460 --> 00:15:15,710 ‫Layla is going to be female and her university will be Beijing Tech and the last one will be James. 205 00:15:16,580 --> 00:15:20,420 ‫And James is a transgender. 206 00:15:21,020 --> 00:15:23,330 ‫So we have three genders here as well. 207 00:15:23,330 --> 00:15:26,000 ‫And this one will be Beijing Tech. 208 00:15:26,750 --> 00:15:27,440 ‫All right. 209 00:15:27,440 --> 00:15:30,770 ‫So that we are we can insert students very easily. 210 00:15:30,770 --> 00:15:32,600 ‫And now for use a little challenge. 211 00:15:32,600 --> 00:15:34,400 ‫Add that to the data context. 212 00:15:36,330 --> 00:15:36,630 ‫All right. 213 00:15:36,630 --> 00:15:37,650 ‫I hope you tried it. 214 00:15:37,680 --> 00:15:43,410 ‫Data context dot students dot insert all on submit. 215 00:15:43,410 --> 00:15:50,580 ‫So here we used insert on submit and it was just one entry but now insert all and submit takes an i 216 00:15:50,580 --> 00:15:55,290 ‫enumerable so a list I enumerable accepts list. 217 00:15:55,500 --> 00:16:02,010 ‫So this list is of type list, but it's a generic connection, so we can use it in the same way here. 218 00:16:02,010 --> 00:16:07,410 ‫We can just hand over a connection collection here and it will be my students. 219 00:16:07,410 --> 00:16:12,090 ‫So submit students like that. 220 00:16:12,090 --> 00:16:15,330 ‫And of course we need to submit the changes. 221 00:16:15,330 --> 00:16:17,640 ‫So submit changes like that. 222 00:16:17,640 --> 00:16:24,900 ‫And now my main data grid should be item source items source. 223 00:16:25,620 --> 00:16:30,750 ‫And in this case it's my data context dot students. 224 00:16:30,750 --> 00:16:37,920 ‫So now I want to see the students in my grade and it should be those for students. 225 00:16:38,040 --> 00:16:43,650 ‫Now let me call insert students instead of insert universities. 226 00:16:43,650 --> 00:16:47,850 ‫So insert you students here like that. 227 00:16:48,030 --> 00:16:53,160 ‫Now let's run the code and we should see four entries in our table. 228 00:16:54,670 --> 00:17:00,760 ‫And now, as you can see, we have ID, name gender university ID and the university, which in this 229 00:17:00,760 --> 00:17:04,260 ‫case is a link to SQL University. 230 00:17:04,270 --> 00:17:10,270 ‫So it's an object of type link to SQL University, so it doesn't tell us the actual name here within 231 00:17:10,270 --> 00:17:11,260 ‫the university. 232 00:17:11,290 --> 00:17:11,950 ‫All right. 233 00:17:11,950 --> 00:17:17,500 ‫But that's something that we have set up here and in here. 234 00:17:17,500 --> 00:17:21,970 ‫So we said it's the University of Beijing Tech. 235 00:17:21,970 --> 00:17:23,950 ‫It's the University of Beijing Tech. 236 00:17:23,950 --> 00:17:28,990 ‫But these are university objects and they don't equal the name. 237 00:17:28,990 --> 00:17:30,310 ‫So they are more than just the name. 238 00:17:30,310 --> 00:17:32,800 ‫They are the actual university object in there. 239 00:17:32,800 --> 00:17:41,680 ‫But other than that, you see that we have Carla, Toni, Layla, Layla, Jane and well, I didn't write 240 00:17:41,680 --> 00:17:47,020 ‫the names correctly, but we have also the gender and the university ID and as you might remember, 241 00:17:47,020 --> 00:17:53,200 ‫University ID six was Yale and University ID seven was Beijing Tech. 242 00:17:53,200 --> 00:17:56,650 ‫And that was because I deleted entries. 243 00:17:56,650 --> 00:18:02,500 ‫And then I call this insert university method multiple times, and that's why we had those IDs instead 244 00:18:02,500 --> 00:18:03,700 ‫of one and two. 245 00:18:05,280 --> 00:18:05,850 ‫All righty. 246 00:18:05,850 --> 00:18:09,300 ‫So if we check out our data, we should see the same thing. 247 00:18:09,300 --> 00:18:10,490 ‫So let's do that. 248 00:18:10,500 --> 00:18:13,470 ‫Let's check out our student data. 249 00:18:13,890 --> 00:18:16,530 ‫Show table data or data table. 250 00:18:16,530 --> 00:18:19,020 ‫We see Karla female. 251 00:18:19,020 --> 00:18:22,590 ‫And what you also see is university ID. 252 00:18:22,860 --> 00:18:26,370 ‫So there is no additional column called universities. 253 00:18:26,770 --> 00:18:29,940 ‫That's something that we have just set up with code here as well. 254 00:18:29,940 --> 00:18:36,450 ‫So we didn't create them permanently, but we set them up here and they are displayed because the data 255 00:18:36,450 --> 00:18:41,100 ‫context contains them as we have added them in here, you see. 256 00:18:41,790 --> 00:18:42,600 ‫Okay. 257 00:18:42,780 --> 00:18:53,010 ‫So that's quite a bit about well link and not just that, we also used a lambda function here in this 258 00:18:53,010 --> 00:18:57,000 ‫piece of code and we will do that a little more in the next video. 259 00:18:57,000 --> 00:18:58,950 ‫So no worries, you'll get used to it. 260 00:18:58,950 --> 00:19:04,770 ‫And yeah, in the next video we're going to do something with an associate of table between students 261 00:19:04,770 --> 00:19:05,430 ‫and lectures. 262 00:19:05,430 --> 00:19:10,080 ‫So we're going to add students and we're going to add lectures to the students and so forth. 263 00:19:10,080 --> 00:19:11,910 ‫So see you in the next video.