1 00:00:08,720 --> 00:00:09,920 Welcome back. 2 00:00:09,950 --> 00:00:14,000 In this video, let's see how we can carry a database. 3 00:00:14,000 --> 00:00:19,100 That is how we can find all students by a specific name. 4 00:00:19,310 --> 00:00:27,020 So let's say that in our database, we want to find all student who is from a specific location. 5 00:00:27,050 --> 00:00:30,440 We can do that using what is called find. 6 00:00:30,890 --> 00:00:36,350 Meaning find is going to return all records with specific query. 7 00:00:36,530 --> 00:00:42,680 And if we want to find a single user, we are going to use a different method called find one. 8 00:00:43,070 --> 00:00:45,590 And this is what we call query. 9 00:00:45,620 --> 00:00:50,750 We are going to query our database to retrieve a specific data that we need. 10 00:00:50,780 --> 00:00:53,360 So let me comment this one. 11 00:00:53,780 --> 00:01:01,010 So let's say find a student by name, Emmanuel. 12 00:01:01,220 --> 00:01:02,090 The first step. 13 00:01:02,090 --> 00:01:03,020 So let's see. 14 00:01:03,050 --> 00:01:09,830 Com found student equal to a weight. 15 00:01:09,830 --> 00:01:17,540 And then my student collection on that we have a method called find what you see we have find and then 16 00:01:17,540 --> 00:01:18,580 find one. 17 00:01:18,590 --> 00:01:23,350 What is a difference is well let's take to the find one. 18 00:01:23,360 --> 00:01:26,300 So here we go find one. 19 00:01:26,300 --> 00:01:33,410 Our pass in the argument which is called the query as objects and provide the property name. 20 00:01:33,710 --> 00:01:40,670 So make sure that the property name exists on the document because we have name on the document here. 21 00:01:40,970 --> 00:01:46,010 So here I want to find a student by name who is Emmanuel. 22 00:01:46,040 --> 00:01:50,900 Now, if I console.log, the found student. 23 00:01:50,900 --> 00:01:52,760 Found student. 24 00:01:54,560 --> 00:01:58,850 Let's go ahead and then run and let's see what you're going to get. 25 00:01:59,270 --> 00:02:01,940 And indeed I get the result. 26 00:02:01,970 --> 00:02:11,030 Emmanuel What about if I provide a name which is not in our record, for example, then so save it and 27 00:02:11,030 --> 00:02:12,550 now let's check it out here. 28 00:02:12,560 --> 00:02:16,040 Click the console and let's run the file again. 29 00:02:16,250 --> 00:02:21,500 You can see I got NA meaning that user does not exist. 30 00:02:21,530 --> 00:02:23,480 That is how we make it. 31 00:02:23,660 --> 00:02:28,460 The next step is I want to find all student with specific name. 32 00:02:28,700 --> 00:02:30,500 Okay, so here we go. 33 00:02:30,530 --> 00:02:32,960 The first one is find a student by name. 34 00:02:32,960 --> 00:02:35,260 That is Emmanuel and he's going to be fine. 35 00:02:35,270 --> 00:02:37,520 All student who is from? 36 00:02:38,470 --> 00:02:40,960 Kumasi the city name. 37 00:02:41,520 --> 00:02:46,090 You see that in our database we have to student who is from Kumasi. 38 00:02:46,120 --> 00:02:48,890 The first one is John and then Emmanuel. 39 00:02:48,910 --> 00:02:52,630 So when I make that query, I'm going to get these two students. 40 00:02:52,630 --> 00:02:54,610 So here we go. 41 00:02:54,910 --> 00:03:02,440 So I'll provide our bring in the same command here and then down here, paste it here and change this 42 00:03:02,440 --> 00:03:05,010 one to find has that. 43 00:03:05,020 --> 00:03:07,180 So let me comment this one. 44 00:03:07,180 --> 00:03:11,300 And here are going to be students, plural for students. 45 00:03:11,330 --> 00:03:11,950 Okay. 46 00:03:11,950 --> 00:03:15,760 So here are going to be the student. 47 00:03:16,060 --> 00:03:19,180 So I want to find all student by city. 48 00:03:19,180 --> 00:03:25,550 So here I'm going to be city and the city name going to be as Kumasi. 49 00:03:26,050 --> 00:03:26,530 All right. 50 00:03:26,530 --> 00:03:27,810 So now let's see. 51 00:03:27,820 --> 00:03:30,490 Let's console.log this one or student. 52 00:03:30,490 --> 00:03:33,070 And now back to the terminal here. 53 00:03:33,460 --> 00:03:37,270 Let me clear the terminal and let me run the file again. 54 00:03:37,300 --> 00:03:38,710 Let's see what you're going to get. 55 00:03:38,710 --> 00:03:42,370 Well, I get the same thing as what cursor. 56 00:03:42,370 --> 00:03:44,970 So I need to use what is called array. 57 00:03:44,980 --> 00:03:50,890 So any time you are returning multiple command from MongoDB, unless you convert it to array. 58 00:03:50,890 --> 00:03:59,320 So here are going to be to array as that, save it and now back to the terminal and let's restart it 59 00:03:59,320 --> 00:04:00,250 again. 60 00:04:01,930 --> 00:04:05,230 Click the console and here we go. 61 00:04:05,230 --> 00:04:08,980 Let's see, you're going to have two documents and indeed we have it. 62 00:04:08,980 --> 00:04:12,460 The first one is this one and the second one is this. 63 00:04:12,460 --> 00:04:15,130 Dondo and Emmanuel are from Kumasi.