1
00:00:02,020 --> 00:00:08,620
With size out of the way, let's now have a look at all. For that, I will use the data

2
00:00:08,620 --> 00:00:11,140
I also used in the assignment,

3
00:00:11,390 --> 00:00:14,550
so for me that is stored in the box office database.

4
00:00:14,840 --> 00:00:17,120
So let's use box office

5
00:00:17,120 --> 00:00:21,120
and there if I have a look at all collections, we see there is the movie starts collection.

6
00:00:21,620 --> 00:00:23,650
So I'll work with that movie starts collection,

7
00:00:23,690 --> 00:00:25,110
moviestarts,

8
00:00:25,370 --> 00:00:28,980
let's quickly have a look into it without any filter to see what's in there,

9
00:00:29,000 --> 00:00:36,470
we got three movies and now let's say I want to find movies that have a genre of exactly thriller and

10
00:00:36,470 --> 00:00:43,190
action but I don't care about the order because I've got two movies, this one and this one and they both

11
00:00:43,190 --> 00:00:45,860
only got thriller and action.

12
00:00:45,860 --> 00:00:56,270
The problem I will have is if I use my movie starts here and I find my movies by the genre and I

13
00:00:56,270 --> 00:01:06,310
say it has to be exactly equal to action and thriller, then I will only find one document because only

14
00:01:06,310 --> 00:01:11,920
this document is exactly equal to action being the first element and thriller being the second element

15
00:01:12,010 --> 00:01:13,700
which is what I specified here.

16
00:01:14,020 --> 00:01:20,800
But what if I don't care about the order? Well then, the all operator can help you. For this,

17
00:01:20,800 --> 00:01:28,990
I simply wrap my array in a document where I use $all as operator and that operator receives

18
00:01:29,090 --> 00:01:33,080
my array then and we also need to close that extra curly brace.

19
00:01:33,100 --> 00:01:40,180
What this will do is it will now search genre for these keywords and it will make sure that these items

20
00:01:40,390 --> 00:01:46,060
do have to exist in genre and these items could be numbers, could be embedded documents, could be other arrays

21
00:01:46,060 --> 00:01:47,470
even, doesn't matter

22
00:01:47,470 --> 00:01:51,160
but it ensures that these two elements exist in a genre

23
00:01:51,340 --> 00:01:59,920
but it doesn't care about the order. And therefore now I find both documents even though the order is

24
00:01:59,920 --> 00:02:01,750
different within genre.

25
00:02:02,140 --> 00:02:04,780
So all is really useful if you don't care about the order,

26
00:02:04,810 --> 00:02:08,160
you just want to make sure that all fields are included

27
00:02:08,350 --> 00:02:10,090
but the order does not matter for you.