WEBVTT 00:07.520 --> 00:10.100 I'll come back again to PostgreSQL. 00:10.130 --> 00:16.700 And let's go ahead and look at react class with other classes like the and the or and so on. 00:17.090 --> 00:22.310 So we have done or we've looked at the class previously, but now we have a larger dataset. 00:22.310 --> 00:26.360 I want us to apply this with this dataset. 00:26.360 --> 00:29.870 So I can be able to work with something that looks real. 00:29.900 --> 00:31.340 Now let's see. 00:31.340 --> 00:37.580 We have select all from students and we're able to generate everything from here. 00:37.610 --> 00:41.120 Now what if I want to generate maybe only the students from Nigeria. 00:41.150 --> 00:43.190 Let's go ahead and see how we can be able to do that. 00:43.190 --> 00:53.630 So we'll go ahead and say start from student and then we'll give a react class where uh country is equal 00:53.660 --> 00:54.950 to Nigeria. 00:54.950 --> 01:00.740 So and let's go ahead and is the cutest query on setup. 01:00.800 --> 01:04.820 So now we have our students from Nigeria and we have just seven of them. 01:04.850 --> 01:09.520 Now what if I'm asked to give only the female students from Nigeria. 01:09.550 --> 01:11.230 How can I be able to do that? 01:11.260 --> 01:14.050 I would not cross and I'm going to see. 01:14.080 --> 01:22.390 And then and I'm going to say, and gender is equal to maybe female or male. 01:22.420 --> 01:27.190 So in that case I'm going to say male if that is for male. 01:27.220 --> 01:29.050 And I will execute this query. 01:29.050 --> 01:33.910 And this we have just three male students from Nigeria. 01:34.570 --> 01:43.810 And that is the same thing with all other ones like other columns, if you want to specify or what if 01:43.810 --> 01:53.950 I say select all from uh, all students where the country is equal to Nigeria, then I'm going to add 01:53.980 --> 01:55.240 another country. 01:55.330 --> 02:02.980 And if I want to add another country right in here, you go ahead and uh, let me say to make that easy 02:02.980 --> 02:05.020 for us, I'll go ahead and cut this. 02:05.050 --> 02:10.540 I'm going to say select where gender is equal to no. 02:10.570 --> 02:16.400 Then and I'm going to see an. 02:18.530 --> 02:24.920 Array so and country I'm going to put this country inside here. 02:25.760 --> 02:28.700 Let's go ahead and close this then inside here. 02:28.700 --> 02:31.340 And I'm going to give a necklace code all. 02:31.340 --> 02:38.660 So I'm going to say all country is equal to. 02:41.150 --> 02:45.980 I'm going to let me choose any country and let me say China. 02:46.910 --> 02:49.700 And let's go ahead and execute the query and check it out. 02:49.730 --> 02:57.170 Now we have all these male students from Nigeria and China. 02:57.800 --> 02:58.310 All right. 02:58.310 --> 03:02.690 So let me check a country that is smaller than Ghana Ghana. 03:03.290 --> 03:05.450 And let's go ahead and execute query and check it out. 03:05.480 --> 03:05.810 All right. 03:05.810 --> 03:10.280 So we have just three from Ghana and two from Ghana and three from Nigeria. 03:10.280 --> 03:15.380 So and remember I selected a where gender is equal to male. 03:15.410 --> 03:19.160 What if I go ahead and see where gender is equal to female. 03:19.220 --> 03:21.200 And let's go ahead and coherent is a coherent. 03:21.200 --> 03:21.890 Check it out. 03:21.920 --> 03:25.220 We have no female students from Ghana. 03:25.580 --> 03:35.360 I want to change this to maybe to another country like Poland and execute this query. 03:35.360 --> 03:36.230 We check it out. 03:36.230 --> 03:39.920 So we see you have much students from Poland as well. 03:41.180 --> 03:50.360 Oh so this is also applicable to say let me say select all from students where first name is equal. 03:50.390 --> 04:01.370 To specify the first name, let's say I'm going to say where first underscore name is equal to. 04:01.670 --> 04:05.090 I'm going to copy any of these. 04:05.120 --> 04:06.260 Let me see. 04:09.530 --> 04:11.510 Noah okay. 04:11.510 --> 04:14.780 No it is not far away. 04:14.810 --> 04:16.220 Where is semicolon n. 04:16.250 --> 04:17.900 And that is the query. 04:17.900 --> 04:23.810 And we have these and it says okay we have another from China and Poland. 04:23.810 --> 04:27.650 And what if I want to specify when the country comes from. 04:27.680 --> 04:32.240 So I want to say state oil from students who are first name is equal to none. 04:32.660 --> 04:41.510 And then I want to specify country equal to China. 04:41.570 --> 04:43.550 And let's go ahead and execute this query. 04:43.550 --> 04:46.490 And you can see we're able to filter that. 04:47.150 --> 04:49.280 So it's applicable to email. 04:49.310 --> 04:52.610 You can see we get email is equal to the email we're looking for. 04:52.640 --> 04:55.220 You can also assign the first name is equal to this. 04:55.220 --> 04:59.240 And where the country is equal to this I hope that is cool. 04:59.240 --> 05:05.390 So in that way you can actually filter everything just the way it's supposed to be. 05:05.390 --> 05:12.470 And you can have a clean output and present that to your supervisors or whoever needs that data from 05:12.470 --> 05:13.610 the database. 05:14.120 --> 05:15.620 I hope that is really very cool. 05:15.620 --> 05:19.700 So go ahead and check it out, practice with it, and if you have any questions, go ahead and use the 05:19.700 --> 05:20.900 question and answer section. 05:20.900 --> 05:23.480 And I'm going to get back to you as soon as possible. 05:23.510 --> 05:24.440 Thank you so much. 05:24.440 --> 05:27.500 And I'm going to see you in the next video lecture.