Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated:
1
00:00:01,090 --> 00:00:03,630
Let's now implement result sorting.
2
00:00:03,630 --> 00:00:07,000
In order to enable our users to sort result
3
00:00:07,000 --> 00:00:08,763
based on a certain field.
4
00:00:10,180 --> 00:00:14,033
So, let's now take a look at all our results here for now.
5
00:00:14,970 --> 00:00:17,930
All right, and so let's say that we actually want
6
00:00:17,930 --> 00:00:21,129
to sort these results, let's say by price.
7
00:00:21,129 --> 00:00:24,560
Okay, so starting with the lowest price and then moving up
8
00:00:24,560 --> 00:00:27,300
all the way to the highest price.
9
00:00:27,300 --> 00:00:29,462
All right, so we have all kinds of prices.
10
00:00:29,462 --> 00:00:33,830
397, 497, 1197, 1497, 997.
11
00:00:36,330 --> 00:00:38,950
We have even almost 3,000 here.
12
00:00:38,950 --> 00:00:42,570
Then 1497 and so they're not really in order,
13
00:00:42,570 --> 00:00:47,450
and so let's allow the user to basically sort these results
14
00:00:47,450 --> 00:00:50,963
based on a field that can be passed using the query string.
15
00:00:53,690 --> 00:00:58,663
So let's say we want to sort by price.
16
00:00:59,860 --> 00:01:00,890
All right.
17
00:01:00,890 --> 00:01:03,480
So if we run this now, of course, nothing will happen,
18
00:01:03,480 --> 00:01:05,860
it will still show the exact same nine results
19
00:01:05,860 --> 00:01:09,900
and in the same order, because before in the last lecture,
20
00:01:09,900 --> 00:01:13,710
we filtered out basically this sort field.
21
00:01:13,710 --> 00:01:14,543
Right?
22
00:01:14,543 --> 00:01:16,883
And so let's now actually go ahead and use it.
23
00:01:18,020 --> 00:01:19,120
All right?
24
00:01:19,120 --> 00:01:22,650
So, remember here how we created the query object
25
00:01:22,650 --> 00:01:25,430
and then excluded the sort field here,
26
00:01:25,430 --> 00:01:28,840
so that it didn't pollute our filtering, right?
27
00:01:28,840 --> 00:01:33,073
But now we actually need it and so let's now use it.
28
00:01:34,150 --> 00:01:38,040
So, the third feature here is sorting.
29
00:01:38,040 --> 00:01:39,790
Or actually, well that's the second one,
30
00:01:39,790 --> 00:01:43,977
so let's just call this one 1A and 1B.
31
00:01:43,977 --> 00:01:44,963
All right?
32
00:01:46,400 --> 00:01:51,400
So, let's say that if there actually is a sort,
33
00:01:53,750 --> 00:01:56,980
sort req.query.sort.
34
00:01:56,980 --> 00:01:58,913
Okay, and you see it down here.
35
00:01:59,750 --> 00:02:04,210
Now it's gone because of this error here, but anyway.
36
00:02:04,210 --> 00:02:06,427
From our last request we got, of course,
37
00:02:06,427 --> 00:02:09,289
there's a query object here and so in there
38
00:02:09,289 --> 00:02:12,840
we had the sort property, all right?
39
00:02:12,840 --> 00:02:15,010
And if there is a sort property,
40
00:02:15,010 --> 00:02:16,780
well, that means that then
41
00:02:16,780 --> 00:02:20,935
we want to actually sort the results based on the value.
42
00:02:20,935 --> 00:02:23,400
Now one quick thing that we need to do,
43
00:02:23,400 --> 00:02:26,040
is to change this query of variable here from
44
00:02:26,040 --> 00:02:29,630
a constant to a normal variable.
45
00:02:29,630 --> 00:02:31,420
So let, okay?
46
00:02:31,420 --> 00:02:34,284
'Cause now we actually want to chain something
47
00:02:34,284 --> 00:02:36,000
to this query.
48
00:02:36,000 --> 00:02:39,600
So, the new query will be query.sort.
49
00:02:42,410 --> 00:02:46,580
And we want to sort it by req.query.sort.
50
00:02:48,607 --> 00:02:52,060
All right, 'cause that will be the value of the field,
51
00:02:52,060 --> 00:02:53,760
so in this case price,
52
00:02:53,760 --> 00:02:56,270
and Mongoose will then automatically sort the result
53
00:02:56,270 --> 00:02:57,910
based on the price.
54
00:02:57,910 --> 00:02:59,640
And now in case you're wondering,
55
00:02:59,640 --> 00:03:02,600
why it works this way, so why we did this here,
56
00:03:02,600 --> 00:03:05,910
just remember what we talked about over the last lectures.
57
00:03:05,910 --> 00:03:08,910
So, remember how this tour.find here
58
00:03:08,910 --> 00:03:11,030
is gonna return a query, right?
59
00:03:11,030 --> 00:03:13,320
And so we stored that query object here
60
00:03:13,320 --> 00:03:15,320
in this variable, so that later on
61
00:03:15,320 --> 00:03:17,800
we can keep chaining more methods to it.
62
00:03:17,800 --> 00:03:19,990
So more of these methods that are available
63
00:03:19,990 --> 00:03:23,150
on all documents created through the query class.
64
00:03:23,150 --> 00:03:24,780
Okay, remember that?
65
00:03:24,780 --> 00:03:27,620
I think we talked about that in depth two lectures ago.
66
00:03:27,620 --> 00:03:31,180
So in case this is still a bit confusing to you,
67
00:03:31,180 --> 00:03:32,560
then just go back there
68
00:03:32,560 --> 00:03:36,450
or you can also take a look at the documentation, all right?
69
00:03:36,450 --> 00:03:40,840
Now let's actually test this out.
70
00:03:40,840 --> 00:03:43,500
So sort is still set to price.
71
00:03:43,500 --> 00:03:45,402
So I'll send it now.
72
00:03:45,402 --> 00:03:48,210
Let's take a look at the result.
73
00:03:48,210 --> 00:03:50,250
And indeed we start with the lowest price,
74
00:03:50,250 --> 00:03:52,270
but I think we already had that before.
75
00:03:52,270 --> 00:03:57,270
So we start with 397, then 497, then 997, 1197,
76
00:03:59,310 --> 00:04:04,020
1497, and you see that the prices actually keep increasing.
77
00:04:04,020 --> 00:04:07,523
So 1997, 2997.
78
00:04:08,570 --> 00:04:11,163
And so yeah, indeed, they are now sorted.
79
00:04:12,830 --> 00:04:13,663
Okay?
80
00:04:13,663 --> 00:04:16,610
So we sorted them by the price in an ascending order.
81
00:04:16,610 --> 00:04:19,430
But we can also sort them in a descending order.
82
00:04:19,430 --> 00:04:20,810
That's very simple.
83
00:04:20,810 --> 00:04:24,090
All we have to do is to set as the minus here.
84
00:04:24,090 --> 00:04:27,200
So, minus price and Mongoose will then automatically
85
00:04:27,200 --> 00:04:29,040
sort them in the other order.
86
00:04:29,040 --> 00:04:31,221
So, in the descending order.
87
00:04:31,221 --> 00:04:34,220
So let's test out that one as well.
88
00:04:34,220 --> 00:04:36,750
And so now we should start with, yeah exactly,
89
00:04:36,750 --> 00:04:38,150
with this one.
90
00:04:38,150 --> 00:04:40,190
So, the first one is now the highest
91
00:04:40,190 --> 00:04:43,960
and the last one is the 397 one.
92
00:04:43,960 --> 00:04:44,930
Cool.
93
00:04:44,930 --> 00:04:48,030
But we can actually take it one step further,
94
00:04:48,030 --> 00:04:51,500
because we have many cases here which have the same price.
95
00:04:51,500 --> 00:04:54,390
But how are these results with the same price then
96
00:04:54,390 --> 00:04:56,190
ordered within them?
97
00:04:56,190 --> 00:04:58,468
So let's say we have this one with this price
98
00:04:58,468 --> 00:05:00,700
and then this one with the same price.
99
00:05:00,700 --> 00:05:05,330
So why does this one appear before the second one?
100
00:05:05,330 --> 00:05:08,050
The same thing with this one here maybe,
101
00:05:08,050 --> 00:05:09,720
oh actually not.
102
00:05:09,720 --> 00:05:12,496
So this one is just the only one with 1997.
103
00:05:12,496 --> 00:05:16,650
But then here again we have these two with the same price.
104
00:05:16,650 --> 00:05:21,563
We have, okay, they are all different.
105
00:05:23,360 --> 00:05:25,150
Okay, these are all different.
106
00:05:25,150 --> 00:05:27,610
But we want to rank them, basically,
107
00:05:27,610 --> 00:05:29,900
according to a second criteria.
108
00:05:29,900 --> 00:05:31,790
So in case there is a tie,
109
00:05:31,790 --> 00:05:33,570
then we want to have a second field
110
00:05:33,570 --> 00:05:36,550
by which we can then sort where the first one is the same.
111
00:05:36,550 --> 00:05:38,230
So in this case the price.
112
00:05:38,230 --> 00:05:40,500
So in Mongoose that's quite easy,
113
00:05:40,500 --> 00:05:43,400
and let me show that to you here as a comment for example.
114
00:05:44,450 --> 00:05:47,510
So in Mongoose we would just say sort
115
00:05:49,650 --> 00:05:52,980
and then right now we have the price,
116
00:05:52,980 --> 00:05:54,430
so we have it just like this,
117
00:05:54,430 --> 00:05:56,340
but then in Mongoose all we have to do
118
00:05:56,340 --> 00:05:59,690
is to add another field name to the string.
119
00:05:59,690 --> 00:06:02,563
So for example, rating average.
120
00:06:03,451 --> 00:06:06,130
Or I think it's ratings.
121
00:06:06,130 --> 00:06:10,460
Okay, and so we now want to pass this field here as well
122
00:06:10,460 --> 00:06:11,363
to our sort.
123
00:06:12,640 --> 00:06:13,473
Okay?
124
00:06:13,473 --> 00:06:15,900
Now we cannot leave a space here in the URL
125
00:06:15,900 --> 00:06:17,933
and so instead we're gonna add a comma.
126
00:06:18,880 --> 00:06:19,713
Okay?
127
00:06:19,713 --> 00:06:22,080
So we want to sort first by price
128
00:06:22,080 --> 00:06:25,862
and then as a second criteria, also by ratings average.
129
00:06:25,862 --> 00:06:26,757
Okay?
130
00:06:26,757 --> 00:06:28,440
And so now all we need to do
131
00:06:28,440 --> 00:06:33,060
is to basically replace this comma here with a space.
132
00:06:33,060 --> 00:06:33,893
All right?
133
00:06:33,893 --> 00:06:36,004
And of course, we could have even more fields
134
00:06:36,004 --> 00:06:38,460
by which we sort.
135
00:06:38,460 --> 00:06:39,293
Okay?
136
00:06:39,293 --> 00:06:40,900
But for now let's just leave it like this
137
00:06:40,900 --> 00:06:43,813
and implement it very quickly in our code.
138
00:06:44,820 --> 00:06:45,810
All right?
139
00:06:45,810 --> 00:06:48,543
And actually let me create a new variable here.
140
00:06:49,870 --> 00:06:51,303
Let's call it sort by.
141
00:06:53,014 --> 00:06:57,410
And so we have req.query.sort
142
00:06:57,410 --> 00:07:01,020
and what we're gonna do is to now split it by the comma.
143
00:07:01,020 --> 00:07:05,867
So split the string by the comma,
144
00:07:05,867 --> 00:07:08,220
and so this will then return an array of all the strings,
145
00:07:08,220 --> 00:07:09,720
so all the field names,
146
00:07:09,720 --> 00:07:13,060
and then all we have to do is to put it back together
147
00:07:13,060 --> 00:07:17,453
using join, and as the join string we use a space.
148
00:07:18,490 --> 00:07:19,980
All right?
149
00:07:19,980 --> 00:07:23,223
And so just to make sure that it's correct.
150
00:07:24,280 --> 00:07:29,280
Console.log, sort by, and then of course here
151
00:07:29,363 --> 00:07:32,423
we want to use that sort by variable.
152
00:07:34,280 --> 00:07:35,240
Okay?
153
00:07:35,240 --> 00:07:36,690
So let's take a look at that.
154
00:07:40,450 --> 00:07:41,633
And.
155
00:07:43,350 --> 00:07:48,350
So 4.7 here, and the other one also has 4.7, all right?
156
00:07:48,990 --> 00:07:52,130
And so let's actually go ahead and use our API
157
00:07:52,130 --> 00:07:54,360
to change this ratings average here.
158
00:07:54,360 --> 00:07:55,193
Okay?
159
00:07:55,193 --> 00:07:56,740
So just as a fun experiment,
160
00:07:56,740 --> 00:08:00,483
let's copy this ID here, then update tour,
161
00:08:02,060 --> 00:08:04,440
and so let's come here to the body,
162
00:08:04,440 --> 00:08:08,367
and so I want to update ratings average to 4.9.
163
00:08:13,465 --> 00:08:14,380
Okay?
164
00:08:14,380 --> 00:08:18,513
Let's send that, and indeed, you see that it got updated.
165
00:08:21,120 --> 00:08:22,940
And so now let's change that again,
166
00:08:22,940 --> 00:08:24,700
or let's try that again actually.
167
00:08:24,700 --> 00:08:27,534
And so now you see the first one still has 4.7
168
00:08:27,534 --> 00:08:30,510
and this one here now has 4.9.
169
00:08:30,510 --> 00:08:34,476
And so they are now ordered with an ascending rating.
170
00:08:34,476 --> 00:08:35,600
Right?
171
00:08:35,600 --> 00:08:38,335
And of course, we could put a minus here
172
00:08:38,335 --> 00:08:41,653
and so then they should change positions,
173
00:08:41,653 --> 00:08:45,970
meaning that the one with 4.9 should appear first.
174
00:08:45,970 --> 00:08:47,960
Let's try that as well.
175
00:08:47,960 --> 00:08:50,590
And yeah, indeed.
176
00:08:50,590 --> 00:08:53,010
So now this one, the sports lover tour,
177
00:08:53,010 --> 00:08:55,230
is the one that appears first.
178
00:08:55,230 --> 00:08:56,710
All right, great.
179
00:08:56,710 --> 00:08:58,800
So it looks like it's working.
180
00:08:58,800 --> 00:09:01,270
Let's a take a look at our results here.
181
00:09:01,270 --> 00:09:02,670
And yeah, indeed.
182
00:09:02,670 --> 00:09:04,970
And let's just take a look at what we logged here
183
00:09:04,970 --> 00:09:06,190
at the console.
184
00:09:06,190 --> 00:09:10,453
And so, yeah, this is our sort by variable, which yeah.
185
00:09:11,790 --> 00:09:14,718
Which kind of looks similar to what we have here.
186
00:09:14,718 --> 00:09:17,560
And so that was the goal of creating this variable.
187
00:09:17,560 --> 00:09:19,410
Great, so that's now working.
188
00:09:19,410 --> 00:09:23,263
Let's get rid of this console and this one here as well.
189
00:09:24,430 --> 00:09:26,180
And all right.
190
00:09:26,180 --> 00:09:27,140
And just to finish here,
191
00:09:27,140 --> 00:09:29,910
let's actually add a default one.
192
00:09:29,910 --> 00:09:33,565
And we do that by simply adding an else block here.
193
00:09:33,565 --> 00:09:36,580
So in case that the user does not specify
194
00:09:36,580 --> 00:09:39,770
any sort field in the URL query string,
195
00:09:39,770 --> 00:09:42,583
we're still gonna add a sort to the query.
196
00:09:43,850 --> 00:09:47,300
So query.sort and we will then sort
197
00:09:47,300 --> 00:09:49,990
by the created add field, all right?
198
00:09:49,990 --> 00:09:51,830
And actually in a descending order,
199
00:09:51,830 --> 00:09:54,330
so that the newest ones appear first.
200
00:09:54,330 --> 00:09:59,070
So minus created at.
201
00:09:59,070 --> 00:10:00,050
All right?
202
00:10:00,050 --> 00:10:01,730
Give this a save.
203
00:10:01,730 --> 00:10:05,240
And so yeah, I think like this, we're done.
204
00:10:05,240 --> 00:10:09,140
Let's just turn off this option here as well.
205
00:10:09,140 --> 00:10:12,503
And so now we just are back to our regular URL
206
00:10:13,390 --> 00:10:15,100
without any query strings.
207
00:10:15,100 --> 00:10:16,570
And so let's take a look
208
00:10:16,570 --> 00:10:19,780
if this is now actually ordered by the created at.
209
00:10:19,780 --> 00:10:22,713
So this one here ends in 59 seconds and 30.
210
00:10:23,730 --> 00:10:25,230
5930 as well.
211
00:10:25,230 --> 00:10:27,363
And yeah.
212
00:10:27,363 --> 00:10:29,670
So they were all created at the exact same moment,
213
00:10:29,670 --> 00:10:32,990
because we imported them all at the same time.
214
00:10:32,990 --> 00:10:33,823
All right?
215
00:10:33,823 --> 00:10:36,250
And so in this case, we cannot really see
216
00:10:36,250 --> 00:10:38,920
the effect of this piece of code
217
00:10:38,920 --> 00:10:41,810
that we just added here, but in case these documents
218
00:10:41,810 --> 00:10:44,130
were added at different times, then they would now
219
00:10:44,130 --> 00:10:46,901
be ordered by the date they were created.
220
00:10:46,901 --> 00:10:48,430
All right?
221
00:10:48,430 --> 00:10:50,450
So that's it for sorting.
222
00:10:50,450 --> 00:10:53,320
Next up, we're gonna talk about limiting the fields
223
00:10:53,320 --> 00:10:54,763
that we want in our results.
16754
Can't find what you're looking for?
Get subtitles in any language from opensubtitles.com, and translate them here.