WEBVTT 00:00.320 --> 00:01.070 All right. 00:01.080 --> 00:05.410 So we have one more video here or at least one more tool for the toolbox. 00:05.550 --> 00:11.510 Before we get to the exercise at the end of this section and that tool is something called like. 00:11.790 --> 00:14.360 And I'll start off by saying like is very useful. 00:14.400 --> 00:19.930 It basically allows us to perform better searching of our data. 00:20.010 --> 00:25.590 So if you think of when we saw how to use where where would allow us to find exact matches. 00:25.590 --> 00:26.830 So I could do things like. 00:26.910 --> 00:30.190 So like star from books where title is exact. 00:30.180 --> 00:33.980 The Harry Potter and the Sorcerer's Stone. 00:34.380 --> 00:40.140 But what if I wanted to select all Harry Potter books I would want to do something like select star 00:40.140 --> 00:46.120 from books where Title contains Harry Potter or starts with Harry Potter or something like that. 00:46.290 --> 00:54.510 And we don't have a way of doing that yet until now with like so like allows us to do things like this. 00:54.510 --> 00:56.210 Imagine someone comes into your bookstore. 00:56.310 --> 01:03.220 If we have a bookshop and they say there's a book I'm looking for but I can't remember the title. 01:04.240 --> 01:07.010 I think the author's first name is David. 01:07.330 --> 01:10.450 Or maybe it's Dan or or Dave. 01:10.930 --> 01:15.880 And you could go over to your system has a really helpful bookstore employee and you could just search 01:16.030 --> 01:23.380 for let's say books written by authors whose first name starts with DA which I guess is a very broad 01:23.380 --> 01:30.340 category but you could still do that if you searched for authors at like Barnes Noble or a popular bookshop 01:30.340 --> 01:31.460 or Amazon. 01:31.660 --> 01:35.210 You can do that type of search and it will work. 01:35.260 --> 01:38.100 It's just not that common. 01:38.470 --> 01:43.210 But we could do the same thing for books like I said Harry potter is a good example where we want to 01:43.210 --> 01:48.270 search for all the Harry Potter books not just the exact one word for word matched her character for 01:48.280 --> 01:49.250 character matched. 01:49.510 --> 01:51.180 So that's where Ware comes in. 01:51.190 --> 01:56.380 Now I warn you it's going to look a little bit odd when I show it to you but that's OK. 01:56.680 --> 01:58.170 It's not that complicated. 01:58.180 --> 02:00.110 There's just some weird symbols here. 02:00.970 --> 02:04.840 So here's an example using Like where. 02:04.840 --> 02:11.350 So this is ignoring the first part of the query the select start from the update or the daily or whatever 02:11.350 --> 02:12.170 it is. 02:12.280 --> 02:23.410 So blank where author name like and then in quotes I have this present sign da present sign. 02:24.700 --> 02:30.310 So I'll tell you first of all what this is going to do is find where the author's first name has the 02:30.310 --> 02:32.410 letters DA in it. 02:33.220 --> 02:37.650 And these little things here those percentage symbols kind of like that animation there. 02:37.780 --> 02:40.130 Those are known as wild cards. 02:40.150 --> 02:45.970 So that's basically the way that we specify We want to find author first names where there is something 02:46.450 --> 02:53.050 anything at all it's a wild card so any characters and then these two exact character characters DA 02:53.060 --> 02:54.940 and then anything afterwards. 02:55.780 --> 03:00.770 So it's basically a way of saying whatever blank anything. 03:00.910 --> 03:03.650 DA And then whatever anything else afterwards. 03:04.620 --> 03:11.250 And if we try using this right now actually you'll see what happens if we go over here and we do a select 03:11.700 --> 03:24.470 and let's just do a title and author name from books where will do author name like. 03:24.970 --> 03:30.820 And then this is where we need those wild card symbols and we'll put da in between. 03:30.820 --> 03:39.350 So once again this is saying anything followed by da exactly DA so can't be d and then S and A. 03:39.550 --> 03:42.730 IT HAS TO BE DA and then anything afterwards. 03:42.730 --> 03:47.420 So if I hadn't heard of you'll see that it works. 03:47.500 --> 03:48.550 We get these authors. 03:48.550 --> 03:52.800 Dave Dave Dave David David Dan and Frida. 03:53.440 --> 03:58.020 And you might notice for Frieda that doesn't start with DA and you would be right. 03:58.390 --> 04:04.990 It ends with da but it still meets this queries xpect it still meets the conditions for this query which 04:04.990 --> 04:06.380 is anything. 04:06.410 --> 04:08.130 Da anything. 04:08.620 --> 04:19.930 So in this case it's f r e I d or f r e i is meeting this and then we have da And then this wildcard 04:19.990 --> 04:22.990 there's nothing afterwards and that's perfectly fine. 04:22.990 --> 04:27.240 This is not saying there has to be something after the DNA or something before. 04:27.400 --> 04:30.770 As you can see we're matching da V. 04:31.090 --> 04:34.620 So there's nothing before it that's fine then da. 04:34.750 --> 04:36.540 And then afterwards. 04:36.850 --> 04:39.520 So basically this is all about pattern matching. 04:39.520 --> 04:46.660 And if we wanted to refine this so that we only get author first names that start exactly with Dave 04:47.230 --> 04:54.370 or sorry exactly with Da we can do it like this all we do is leave off the first wildcard the first 04:54.370 --> 04:55.020 percent and so on. 04:55.030 --> 05:02.830 And that says I want to find author first names where they start with da and then anything afterwards. 05:02.830 --> 05:05.010 So it could be Dana David Dave. 05:05.180 --> 05:08.320 Dan Darwin or whatever. 05:08.650 --> 05:15.760 So if we could just make that one small change and we delete that percentage sign you can see Frita 05:15.760 --> 05:16.240 is gone. 05:16.240 --> 05:20.650 I'm sorry Freeda because Freeda no longer fits the pattern that we're matching. 05:21.720 --> 05:27.510 Also it's important to note that it is case insensitive as you can see it is lowercase DNA and it still 05:27.510 --> 05:30.750 matches all these uppercase DS in lowercase A's. 05:31.380 --> 05:36.870 So if I wanted to do something slightly different let's say search all books where the title has the 05:36.870 --> 05:39.610 word the somewhere in there. 05:39.780 --> 05:40.510 It's pretty simple. 05:40.530 --> 05:47.520 It's just a select title from books where title like. 05:48.090 --> 05:54.130 And if I just say that's only going to give me books where exactly the. 05:54.510 --> 05:55.770 And that's not what we want. 05:55.770 --> 06:01.680 So we want something followed by the end if we just leave it like this. 06:01.830 --> 06:06.930 That's not going to give us anything because this is specifying we want books where the title has anything 06:06.990 --> 06:09.480 and then ends with the letters THG. 06:09.570 --> 06:11.040 That's not really what we want. 06:11.670 --> 06:14.910 So we'll add another wildcard at the end. 06:15.060 --> 06:22.230 And now that gives us all the books that have a title has something then THG and then something else 06:22.230 --> 06:23.140 afterwards. 06:23.610 --> 06:27.640 So you can see if we get the namesake a hologram for the king the circle the masing adventure to Kavli 06:27.650 --> 06:28.410 and clay. 06:28.410 --> 06:30.930 Consider the lobster and then Lincoln in the bardo. 06:31.320 --> 06:32.670 Really good book by the way. 06:32.670 --> 06:34.500 I know I've said it like 10 times. 06:34.510 --> 06:35.690 Good work. 06:36.060 --> 06:42.360 So that's the basics of using like these percentage signs are very common. 06:42.600 --> 06:46.470 I know it looks kind of odd but this is really really important. 06:46.500 --> 06:48.150 Think of when you're searching. 06:48.420 --> 06:53.420 I don't know if you're on if you use read it if you're ever searching for things on Reddit. 06:53.490 --> 07:00.860 Behind the Scenes like is being employed or if you're searching on whatever site you search on there's 07:00.870 --> 07:06.280 some form of variation of this like going on where you're query whatever you search for. 07:06.810 --> 07:09.000 It's not being it's not only matching. 07:09.000 --> 07:10.230 Exactly. 07:10.230 --> 07:13.940 So when I search for you know on Amazon I type in. 07:14.070 --> 07:17.520 Let's let's just go with my let's say Lord Of The Rings I search Lord Of The Rings. 07:17.550 --> 07:19.880 It's not only going to give me books that have a title. 07:19.920 --> 07:20.870 Exactly. 07:20.920 --> 07:21.860 Of Lord Of The Rings. 07:22.070 --> 07:25.040 It's going to give me books that have Lord Of The Rings in the title somewhere. 07:25.290 --> 07:30.600 Obviously their search is much much more complicated where it also searches things like you know through 07:30.600 --> 07:33.900 comments and reviews and related books. 07:33.900 --> 07:37.800 And there's this whole complicated graph network of how the search works. 07:37.800 --> 07:42.210 But the core idea the simplest search that you could implement uses like.