WEBVTT 00:07.670 --> 00:10.880 I will call you back again to another video lecture in MySQL. 00:10.880 --> 00:18.530 And in this video lecture we go ahead and look at what is known as autocommit commit and rollback. 00:18.530 --> 00:24.140 So this three key ways we have asked to be able to work with our database safely. 00:24.140 --> 00:29.210 So you can remember that when we try to delete our database I told you not to do that. 00:29.240 --> 00:32.960 So I said delete from a strings. 00:32.960 --> 00:34.910 So under action how to do this. 00:34.910 --> 00:36.530 Because if we do that it's dangerous. 00:36.560 --> 00:38.600 It's going to delete whatever that we have here. 00:38.690 --> 00:44.000 The reason is because I have not been able to save this. 00:44.030 --> 00:48.560 The reason is that I need to put this in a mode that will help me to recover whatever I do, and that 00:48.560 --> 00:51.380 is where Autocommit comes into play. 00:51.410 --> 00:57.740 Now, if I go ahead and, uh, set Autocommit equal to zero, it means that this will not be committed. 00:57.740 --> 01:02.680 It will not be, uh, once we execute the query, it's not going to be saved automatically. 01:02.710 --> 01:03.460 All right. 01:03.610 --> 01:05.890 Go ahead and say set. 01:06.220 --> 01:16.960 And then I'm going to say set a autocommit and let autocommit be equal to all. 01:16.990 --> 01:19.330 And then go ahead and press semicolon at the end. 01:19.360 --> 01:21.700 Now I'll go ahead and execute this query. 01:21.700 --> 01:26.230 And down here you can see that we have set autocommit equal to f. 01:26.290 --> 01:31.990 And we set autocommit because of a warhead and the commit that. 01:32.260 --> 01:32.710 All right. 01:32.710 --> 01:34.450 So go ahead and commit this. 01:34.450 --> 01:39.100 And if you go ahead and hit on commit you can see down here we have commit. 01:39.100 --> 01:42.970 And that is green showing that you have already committed this. 01:43.000 --> 01:46.240 Now anytime I use commit it means I want to save this. 01:46.270 --> 01:46.720 All right. 01:46.720 --> 01:49.300 So anytime I say commit it means I want to save it. 01:49.300 --> 01:51.340 And that is why I'm using commit. 01:51.550 --> 01:57.190 But if I don't use commit it will not be saved automatically because I have disable auto commit. 01:57.220 --> 01:57.610 All right. 01:57.610 --> 01:59.680 So we have to always manually save it. 01:59.700 --> 02:01.920 Now I can confidently go ahead. 02:02.130 --> 02:05.910 And first of all, maybe I say delete. 02:06.690 --> 02:11.520 So delete are from students. 02:11.520 --> 02:12.810 So they're from students. 02:12.810 --> 02:19.230 Then first of all we are class because I want us to be safe and do this step by step. 02:19.230 --> 02:21.570 We are students. 02:22.950 --> 02:31.650 So we are students are ID is equal to let me say eight and then we call end. 02:31.680 --> 02:37.500 And then we go ahead and show that as guidance say select. 02:37.920 --> 02:44.070 And then we can now say from students and put semicolon. 02:44.190 --> 02:47.610 And now this corps had and the is the key to this query. 02:47.610 --> 02:49.440 And then let's go ahead and check. 02:49.470 --> 02:54.900 So the students are just who have deleted this all right. 02:54.900 --> 02:56.190 And is no longer here. 02:56.190 --> 02:59.690 And now if we want to get that back again. 02:59.720 --> 03:02.930 I'll go over here and remove this arm is what's called rollback. 03:02.930 --> 03:06.020 So this is a keyword to say rollback. 03:06.020 --> 03:09.800 And then we call it end and execute this. 03:09.830 --> 03:13.790 Now you can see I have Steve right in here back again. 03:13.790 --> 03:17.690 So I can confidently now tell you to delete. 03:17.690 --> 03:20.030 And you go ahead and delete. 03:20.060 --> 03:32.570 But if I should go ahead and say delete and then I'll go ahead and say from students. 03:32.750 --> 03:40.010 And then we're then we're going to say we are the student ID. 03:42.050 --> 03:45.020 Is equal to eight, which is just Steve. 03:45.020 --> 03:46.760 And then put a semicolon at the end. 03:46.760 --> 03:49.880 And let's go ahead and execute this query again. 03:49.910 --> 03:52.610 Now Judge Steve is no longer there. 03:52.640 --> 03:56.660 Now I'll go ahead and say commit. 03:57.770 --> 03:58.100 All right. 03:58.130 --> 04:00.640 So our I always use a uppercase. 04:00.640 --> 04:04.240 So commit a semicolon at the end. 04:04.270 --> 04:05.740 Now go ahead and execute this. 04:05.890 --> 04:10.810 So now you can see we have a this already saved. 04:10.840 --> 04:17.140 If I should go ahead and roll back I'm not going to get anything called Judge Steve again because it 04:17.140 --> 04:18.700 is already committed. 04:18.700 --> 04:25.510 And now you can see that, uh, Judge Steve is entirely wiped off because I have already committed. 04:25.510 --> 04:29.830 So the auto commit has been set off by my analysis of this, by myself. 04:29.860 --> 04:39.730 Now, if I should go ahead and, uh, say delete and I'm going to say delete, uh, from students, 04:39.760 --> 04:44.050 and this is going to intend to wipe out everything we have here. 04:44.080 --> 04:46.000 Go ahead and run this. 04:46.000 --> 04:49.390 And you can see that our table is entirely empty. 04:49.630 --> 04:53.950 We can always use a rule back because we have not committed this automatically. 04:53.980 --> 04:56.530 So go ahead and say rule back. 04:57.870 --> 05:00.960 So grow back and then go ahead and execute this. 05:00.960 --> 05:05.610 And you can see how my table board church two is no longer there because I've already committed that 05:05.610 --> 05:06.150 already. 05:06.150 --> 05:12.780 So you can see that this isn't the commit we can go to manually actually commit our save this. 05:12.810 --> 05:13.110 Right. 05:13.140 --> 05:16.740 So in this video lecture we are able to discuss about auto commit. 05:16.770 --> 05:19.440 We know how to set up auto commit equal to off. 05:19.440 --> 05:20.850 And we can. 05:20.880 --> 05:30.480 We always go ahead and save it manually by using the commit keyword and this query to receive our project. 05:30.480 --> 05:38.550 So in that you can actually uh, delete and then go back to what you have previously and you can actually 05:38.550 --> 05:40.260 recover whatever you just did. 05:40.260 --> 05:41.310 So that is cool. 05:41.310 --> 05:42.600 So let's run with it. 05:42.600 --> 05:45.810 And if you have any question please go ahead and use the question and answer section. 05:45.810 --> 05:48.210 And I'm going to see in the next video lecture. 05:56.040 --> 05:56.520 Nine.