WEBVTT 00:00.240 --> 00:07.680 OK so what we've seen so far allows us to specify what columns we want name and age only or only easy 00:08.100 --> 00:11.490 but it still gives us every single result in the table. 00:11.760 --> 00:17.910 So if we have 10000 users in our database if we wanted to select one we don't have a way of doing that 00:17.910 --> 00:18.600 right now. 00:18.750 --> 00:22.550 We only can select all of them which really is not that useful. 00:22.570 --> 00:27.210 In fact most of the time when you're selecting things you're doing it deliberately and you're trying 00:27.210 --> 00:28.700 to find particular pieces. 00:28.740 --> 00:32.020 You're not just trying to check in on your table make sure everything's OK. 00:32.070 --> 00:38.610 You're usually trying to let's say sign someone in if it's an application you're trying to verify find 00:38.610 --> 00:44.520 someone by their user name and check if their password matches that they entered into your website or 00:44.520 --> 00:47.380 something like that where you're searching for specific data. 00:47.700 --> 00:51.710 And to do that we need to use what's known as the WHERE clause. 00:51.930 --> 00:56.310 So it's another magic keyword where it allows us to get specific. 00:56.310 --> 01:04.500 It allows us to say I want all cats who are 4 years old or I want all cats who are Tabby's and those 01:04.500 --> 01:05.760 are very simple examples. 01:06.060 --> 01:12.130 But later on throughout this course we'll continue to expand your arsenal for select and for searching. 01:12.240 --> 01:19.350 You'll be able to do things like I want all cats that are Tabby's between the age of 1 and 2 and whose 01:19.350 --> 01:21.510 name starts with the letter B. 01:21.530 --> 01:22.280 Let's say. 01:22.380 --> 01:24.140 So we'll be able to get much more specific. 01:24.150 --> 01:27.090 But for now we're focusing on the basics. 01:27.240 --> 01:31.720 And as a side note I want to show you that we will use where all the time. 01:31.720 --> 01:37.200 So it's not just for searching or for selecting But we'll need to use it when we're updating or deleting 01:37.200 --> 01:42.370 things as well because we're trying to update every single thing or delete every single thing. 01:42.510 --> 01:50.370 Usually we want to update something specific so we might say I want to update the cats where their age 01:50.370 --> 01:57.290 is too and I want to make their age three versus I want to update every single cat to have an age of 01:57.290 --> 01:57.830 three. 01:57.950 --> 02:00.070 We could be more targeted using WHERE. 02:00.470 --> 02:03.930 So we're going to start by seeing how we use it to select. 02:04.170 --> 02:05.660 So here's an example. 02:05.660 --> 02:12.260 Select the star from cats where age is for so notice the syntax here. 02:12.430 --> 02:18.880 We have our same select star from CAS that will give us all cats but then we have this where age equals 02:18.880 --> 02:20.290 four. 02:20.290 --> 02:28.550 So what this will do is only select the data from the cat's table where the age column is equal to four. 02:29.170 --> 02:38.650 And if we try that now if we look at our data actually you'll see we have two cats Ringo and egg who 02:38.650 --> 02:41.080 are both four years old. 02:41.080 --> 02:43.950 So if we do a select start from cats you see what we get. 02:44.140 --> 02:53.480 But now if we modify that with our where age equals four semi-colon we only get those two results. 02:53.500 --> 02:59.600 So we still get cat ID name breed and age because we you start that tells us the columns. 02:59.800 --> 03:04.590 But now we only have two results because we used where to get specific. 03:04.660 --> 03:09.680 One note noticed that when I refer to age here that is the column age. 03:09.710 --> 03:11.170 There's no quotes around it. 03:11.290 --> 03:13.690 It's just age. 03:13.690 --> 03:20.560 So we can do the same thing here but this time I'm using name to drill down or to get specific. 03:20.560 --> 03:22.160 So select star from cat. 03:22.240 --> 03:24.350 Name is equal to egg. 03:24.520 --> 03:29.520 And notice I use quotes here because it's no longer an integer like ages. 03:29.980 --> 03:31.230 Name is far char. 03:31.450 --> 03:32.200 It's text. 03:32.200 --> 03:34.740 So we need those quotes so we can try that. 03:34.740 --> 03:42.680 Now select star from cats where name equals egg. 03:42.820 --> 03:50.130 Just like that you notice we get egg cat ID name breed and age. 03:50.170 --> 03:55.290 One side note while I'm here you may come across as at some point. 03:55.390 --> 03:58.410 What do you think will happen if I fully capitalize eg. 04:01.140 --> 04:02.790 It still works. 04:02.790 --> 04:07.290 So it's important to note that by default this is case insensitive. 04:07.380 --> 04:14.040 So I could do lowercase g uppercase G and it still gives me the same data. 04:14.430 --> 04:16.480 So we'll see ways around this later on. 04:16.500 --> 04:22.710 Oftentimes it is useful though to not worry about case if you're dealing with things like an email address 04:23.220 --> 04:24.840 where case doesn't actually matter. 04:25.020 --> 04:30.540 So if a user types in their email with a capital letter at the beginning versus lower case it should 04:30.540 --> 04:32.650 still be the same email in your database. 04:32.790 --> 04:33.990 But we'll talk about that later. 04:33.990 --> 04:40.410 I just wanted to point out that the thing case insensitivity So that's all there is for now to the where 04:40.410 --> 04:40.910 clause. 04:40.980 --> 04:44.790 Now there is a lot more that we will be seeing and working with like I mentioned at the beginning of 04:44.790 --> 04:48.540 this lesson we will come back and use where all the time. 04:48.540 --> 04:52.210 And in fact we're going to continue to use it for updating and deleting. 04:52.230 --> 04:56.860 Like I said we need to specify what we want to delete and what we want to update. 04:57.270 --> 05:01.680 But I just want to make it clear we're not done with where there's a lot of add on functionality that 05:01.680 --> 05:04.140 we'll see in ensuing sections. 05:04.140 --> 05:04.680 Perfect.