1
00:00:02,150 --> 00:00:08,550
With those basics about the data, the documents and how we work with data out of the way,

2
00:00:08,810 --> 00:00:15,970
let's shift our focus towards the crud operations and how we work with the different crud operations

3
00:00:15,980 --> 00:00:17,840
we may use in mongodb.

4
00:00:17,840 --> 00:00:20,830
Now first of all, what is crud all about,

5
00:00:20,860 --> 00:00:22,520
why does this matter?

6
00:00:22,550 --> 00:00:28,550
You can use mongodb for a broad variety of things, you might be building an application or you

7
00:00:28,550 --> 00:00:34,570
have some data which is shipped to you as one file and you just want to run some analytics on it or you're

8
00:00:34,610 --> 00:00:38,450
an administrator of a database, of a mongo database,

9
00:00:38,630 --> 00:00:42,170
in all these cases, you will have to interact with the database.

10
00:00:42,350 --> 00:00:48,320
Now in the application case, you might have an app, a mobile app or a website where user interacts

11
00:00:48,320 --> 00:00:50,440
with your code in the end

12
00:00:50,570 --> 00:00:57,470
and that code can be written in nodejs, php, can be a desktop app written in C++,

13
00:00:57,530 --> 00:01:03,800
really no limits there and you will have your mongodb driver included in your application then. In

14
00:01:04,080 --> 00:01:05,870
the other cases like for analytics,

15
00:01:05,870 --> 00:01:12,260
you might be using the business intelligence connector mongodb offers or you directly use the shell

16
00:01:12,290 --> 00:01:18,830
or some other import mechanism provided by your favorite BI tool or as an administrator, you'll work

17
00:01:18,830 --> 00:01:23,690
with the shell like we're doing it right now. In all these cases, you want to interact with your mongodb

18
00:01:23,690 --> 00:01:27,180
server and for an application like a website,

19
00:01:27,200 --> 00:01:33,430
you typically want to be able to create elements, you want to be able to read, update and delete them.

20
00:01:33,560 --> 00:01:34,860
Let's say you were building a blog,

21
00:01:34,880 --> 00:01:39,760
you want to be able to create new posts, to deliver those posts to your users,

22
00:01:39,800 --> 00:01:42,010
you want to be able to update these posts,

23
00:01:42,050 --> 00:01:48,980
so to change them or maybe even delete them. With analytics, you also at least want to be able to read

24
00:01:48,980 --> 00:01:49,640
the data,

25
00:01:49,640 --> 00:01:52,490
you might never change it but you want to read it

26
00:01:52,730 --> 00:01:58,640
and as an admin, you might want to do all these things to fix some data or to play around with it as

27
00:01:58,640 --> 00:01:59,820
we are doing it.

28
00:01:59,840 --> 00:02:02,520
So these are these core crud operations

29
00:02:02,600 --> 00:02:06,510
and in the end, these operations are the only thing you do with your data,

30
00:02:06,530 --> 00:02:10,740
this is what you have your data for, to create it, manage it, read it,

31
00:02:10,820 --> 00:02:14,560
all these things and you do these things with the mongodb server

32
00:02:14,690 --> 00:02:22,450
and there of course, in the end on a collection and the documents in that collection. Now for these crud operations,

33
00:02:22,600 --> 00:02:29,970
we have a couple of important queries you should keep in mind and you'll also find in the official docs

34
00:02:29,970 --> 00:02:34,980
of course in case you want to check out all the details or dive a bit deeper.

35
00:02:35,160 --> 00:02:37,430
There is insertOne which we already saw,

36
00:02:37,590 --> 00:02:43,860
insertOne allows us to insert some data into a collection and all these methods I'm showing you are

37
00:02:43,860 --> 00:02:48,610
directly executed on a collection as we did it in the last lectures

38
00:02:49,050 --> 00:02:52,900
and we can also pass some options along with insertOne,

39
00:02:53,040 --> 00:02:54,760
we'll not to worry about that right now,

40
00:02:54,810 --> 00:02:57,690
we'll dive into that later though.

41
00:02:57,690 --> 00:03:02,250
Besides inserting one document, we can also insert many documents by the way,

42
00:03:02,310 --> 00:03:07,470
so if you have a use case where you need to insert more than one document at a time, you can do that

43
00:03:07,530 --> 00:03:08,410
too,

44
00:03:08,940 --> 00:03:12,600
this is important for creating data. Now for reading data,

45
00:03:12,600 --> 00:03:17,830
we got find and find also allows us to pass in some arguments.

46
00:03:17,850 --> 00:03:21,940
Right now we're calling it without anything, just find empty parentheses,

47
00:03:22,140 --> 00:03:26,170
now you can pass in a filter and filters are very powerful,

48
00:03:26,190 --> 00:03:30,710
they allow you to narrow down the data you're retrieving, something you of course often want to do in

49
00:03:30,720 --> 00:03:34,550
a database and you can also pass some options to find

50
00:03:34,800 --> 00:03:40,040
and again, we'll take a close look at all these options and filters throughout the course too.

51
00:03:40,500 --> 00:03:42,140
You also got find one,

52
00:03:42,180 --> 00:03:49,140
the difference here is that find finds all matching documents, find one simply gives you the first matching

53
00:03:49,140 --> 00:03:55,900
document it finds. Update one is then useful for changing one piece of data

54
00:03:56,070 --> 00:03:59,330
and just as we can insert many documents at once,

55
00:03:59,370 --> 00:04:06,540
we also have update many. Now the update functions take three arguments because we can pass a filter to

56
00:04:06,540 --> 00:04:12,570
narrow down which document or documents to change then the data describing the change,

57
00:04:12,570 --> 00:04:14,110
so what should be changed

58
00:04:14,220 --> 00:04:18,350
and again some options we can use to configure that process.

59
00:04:18,360 --> 00:04:24,450
We also got replace one in case we just want to replace a document entirely with a new one.

60
00:04:26,030 --> 00:04:27,570
There also is delete,

61
00:04:27,770 --> 00:04:34,610
we can delete one or delete many documents in a collection and there we also pass in a filter to find

62
00:04:34,610 --> 00:04:37,640
out which document or documents to delete.

63
00:04:37,640 --> 00:04:40,490
Now let's see all these things at an example,

64
00:04:40,700 --> 00:04:44,660
again having a look at our flight data here which could look like this,

65
00:04:44,660 --> 00:04:52,430
basically the data we already worked with and there, let's say this is the data we're using on our application.

66
00:04:52,490 --> 00:04:59,330
Our application might be a website where people working at an airport or at an airline can schedule

67
00:04:59,480 --> 00:05:00,680
a new flight,

68
00:05:00,770 --> 00:05:04,940
therefore they would create an entry in our flight data collection,

69
00:05:05,030 --> 00:05:09,350
they can change information about this flight so they can update information,

70
00:05:09,350 --> 00:05:16,190
for example if the aircraft changed, they can cancel the flight let's say so they can delete it and

71
00:05:16,220 --> 00:05:21,830
they can also display flight information on their own website in the mobile apps for their passengers

72
00:05:22,700 --> 00:05:27,480
and therefore, they need to be able or you need to be able to read the data from this collection.

73
00:05:27,500 --> 00:05:31,070
This is our little example here using the data we already set up.

74
00:05:31,100 --> 00:05:35,390
So let's get started and play around with this crud operations and our data.