WEBVTT 00:07.790 --> 00:11.240 I welcome you back again to the lecture on PostgreSQL. 00:11.240 --> 00:14.570 And let's go ahead and learn how to drop the database. 00:15.470 --> 00:15.770 All right. 00:15.800 --> 00:17.990 So what is a database called students. 00:17.990 --> 00:20.420 And we can actually drop that database. 00:20.420 --> 00:30.290 But this is a very dangerous command in PostgreSQL or in any SQL development or in database. 00:31.100 --> 00:38.060 Why is that a dangerous command is because something you've worked for over a long time can be deleted 00:38.090 --> 00:39.620 within a twinkle of an eye. 00:39.740 --> 00:46.310 So if we want to drop a database, you should always know that the database you want to drop is a database 00:46.310 --> 00:47.480 you don't need. 00:47.480 --> 00:50.450 So if it's a database that you need, you don't. 00:50.450 --> 00:55.490 Kohat just drop that because you're going to lose every information there. 00:55.490 --> 01:05.240 So imagine you have a database, uh, which contains millions of data, login details, passwords and 01:05.360 --> 01:07.580 email addresses and so many more. 01:07.580 --> 01:09.800 And you mistakenly drop that database. 01:09.830 --> 01:16.960 You cannot get that again, except you have a bug of some way which you can actually retrieve and work 01:16.960 --> 01:17.380 on. 01:17.410 --> 01:20.140 So let me go ahead and show you how to drop a database. 01:20.170 --> 01:24.160 Now go over here and let's go ahead and list all our database. 01:24.160 --> 01:30.220 So whenever you write backward slash L it means backward slash list. 01:30.220 --> 01:34.120 And if you click on that you're going to see every database you have. 01:34.150 --> 01:39.520 Now if I want to drop a database all I need to do is go ahead and save drop. 01:39.520 --> 01:41.920 And I'm going to see database. 01:41.920 --> 01:44.320 Then I'm going to give the name of the database. 01:44.320 --> 01:45.640 So overriding day. 01:45.640 --> 01:47.800 And I'm going to select student. 01:47.800 --> 01:50.020 And then put a semicolon at the end. 01:50.020 --> 01:52.150 And go ahead and hit enter. 01:52.300 --> 01:54.280 And your database will drop. 01:54.310 --> 01:54.880 All right. 01:54.880 --> 02:01.120 So that is coming off in a very soon it's going to drop he says error database student is being accessed 02:01.120 --> 02:02.110 by other users. 02:02.170 --> 02:05.230 That is one other session is in the database. 02:05.260 --> 02:05.740 All right. 02:05.740 --> 02:08.110 What I want is that I have my admin. 02:08.110 --> 02:15.580 And all I need to do is I can actually go ahead and close the admin, and then I'll open it up again, 02:15.580 --> 02:22.750 and then the database will be dropped because I'm running admin and I'm running the show as well. 02:22.750 --> 02:25.410 So go ahead and, uh, close this. 02:25.440 --> 02:26.760 Let's go ahead and close this. 02:26.760 --> 02:30.810 And it says, do you want to quit the application? 02:30.840 --> 02:31.620 Yes. 02:31.620 --> 02:35.550 And now let's completely go ahead and drop this database again. 02:35.550 --> 02:46.980 So go ahead and say drop that, uh, base and the student employee semicolon and go ahead and uh you 02:46.980 --> 02:48.900 can see drop database. 02:48.900 --> 02:55.380 So whenever you're using Pgadmin and uh SQL shell, these are two different applications. 02:55.380 --> 03:00.750 You either use the graphical interface, the application that is the admin is a graphical interface 03:00.750 --> 03:04.890 application where we can be able to actually do exactly the same thing we are doing right in here. 03:04.920 --> 03:06.930 I'm going to show you one example on that. 03:06.930 --> 03:12.060 So as time goes on, we're going to see an example of how to use the admin graphical user interface 03:12.060 --> 03:13.410 to write queries. 03:13.440 --> 03:14.070 All right. 03:14.100 --> 03:20.820 Now I'm going to also maintain the use of uh SQL in this course because that is one of the defaults 03:20.820 --> 03:26.070 that is most lovable that people use in writing PostgreSQL queries right now. 03:26.070 --> 03:33.120 If you go ahead and open Pgadmin over here, you can see I have only one and I have only Postgres that 03:33.120 --> 03:33.540 is here. 03:33.810 --> 03:34.530 All right. 03:34.530 --> 03:40.770 So the student database has been dropped and I can go back and create that database again. 03:40.800 --> 03:53.970 Go ahead and uh c create database and uh just to the inspiration icon and, and and I'm going to click 03:53.970 --> 03:55.740 on this and it creates a database. 03:55.740 --> 04:01.440 So you can see that why I open up this I was able to create a database because I'm doing a simple action 04:01.440 --> 04:03.030 that is acceptable. 04:03.060 --> 04:08.400 But what I wanted to drop this database, it let me know that this database is open somewhere showing 04:08.400 --> 04:10.680 that that command is very, very dangerous. 04:10.710 --> 04:15.240 Now I can go over here and refresh this and I'm going to see students. 04:15.420 --> 04:16.110 You see that. 04:16.110 --> 04:18.900 And the students database has been created again. 04:18.900 --> 04:23.310 So go ahead and uh create a third database and drop it. 04:23.310 --> 04:27.120 So you can actually learn how to drop a database in PostgreSQL. 04:27.120 --> 04:28.890 And that is very interesting. 04:28.890 --> 04:33.510 So if you have any question under this course, had I use the question and answer section, and I'm 04:33.510 --> 04:35.940 going to get back to you as soon as possible. 04:35.970 --> 04:36.930 Thank you so much. 04:36.930 --> 04:40.080 And I'm going to see you in the next video lecture.