WEBVTT 00:07.610 --> 00:10.580 I welcome you back again to another video lecture in MySQL. 00:10.580 --> 00:16.940 And in this video lecture let's go ahead and learn about auto increment of I. 00:16.940 --> 00:20.270 So in the previous lecture we discussed about the primary keys. 00:20.300 --> 00:25.910 Now if you want to add the auto increment that auto increment should be associated with your primary 00:25.910 --> 00:26.180 key. 00:26.180 --> 00:32.780 So any column that you add the primary key to you go ahead and add auto increment to that. 00:32.780 --> 00:35.420 So that is why it's always good to add that to the ID. 00:35.420 --> 00:38.420 So our ID will automatically be incremented. 00:38.420 --> 00:42.200 So we don't just need to add the ID by ourselves. 00:42.200 --> 00:49.340 So whenever we want to insert a name or anything inside our database, the ID will automatically increment. 00:49.340 --> 00:51.020 And that is how it's supposed to be. 00:51.050 --> 00:58.280 We don't need to always add that maybe 123456, because your database might get up to a million and 00:58.280 --> 00:59.600 you don't even know where you stopped. 00:59.600 --> 01:03.920 So how can you be able to add the ID by yourself every time? 01:04.130 --> 01:08.120 So in order to overcome this issue by adding the ID ourself. 01:08.120 --> 01:13.490 We just need to impute people's data and we go ahead and get the ID automatically inserted. 01:13.490 --> 01:19.280 And then governments know you by your ID, and that ID will automatically be there and it will automatically 01:19.280 --> 01:20.480 be created for you. 01:20.510 --> 01:22.460 So how can we be able to do that? 01:22.640 --> 01:27.830 Oh, and before we do that, you can see I've deleted the teachers table I created here. 01:27.860 --> 01:33.470 You can go ahead and use maybe the employees table or the students table or anyone, but I deleted or 01:33.470 --> 01:39.260 dropped the teachers table so that I can actually use the teachers table to help us to understand what 01:39.260 --> 01:39.950 we are doing. 01:39.980 --> 01:43.580 We just need to insert only the ID and the first name. 01:43.580 --> 01:50.090 You can go ahead and add last name or salary, GP, anything and so on. 01:50.510 --> 01:53.630 So now in a table has been dropped. 01:53.660 --> 01:59.060 I need to create a new teachers table with a primary key and auto increment there. 01:59.060 --> 02:03.110 So in order to do that let's go ahead and create a new table. 02:03.110 --> 02:04.790 So go ahead and say table. 02:04.790 --> 02:08.810 And the table name is going to be teachers. 02:08.930 --> 02:12.610 And we're going to have less Mr. Macron at the end of this. 02:12.880 --> 02:20.140 So inside the teacher's table, we go ahead and, uh, add a touch ID, right? 02:20.170 --> 02:25.000 So touch ID now the add is going to be integer variable. 02:25.000 --> 02:29.020 And the data type is integer and not integer variable. 02:29.020 --> 02:34.030 So the teacher's id has a data type of int for integers. 02:34.030 --> 02:37.750 And then it's going to also be the primary key. 02:37.750 --> 02:45.100 And now we have added a primary key to the teacher's ID we go ahead and add the auto increment. 02:45.100 --> 02:48.250 So go ahead and say auto increment. 02:48.250 --> 02:51.370 And I'll put a comma at the end of that. 02:51.370 --> 02:56.260 Now the auto increment will help the ID to always increment on its own. 02:56.260 --> 02:59.710 We don't need to actually impute that by ourselves. 02:59.740 --> 03:05.350 Now we go ahead and get the critical for the first name. 03:05.350 --> 03:09.190 So I'm going to say first underscore name. 03:09.340 --> 03:12.670 And the data type is varchar. 03:12.970 --> 03:19.990 And the character length is going to be deity and that is all. 03:20.020 --> 03:23.980 Now let's go ahead and select the insert movie to see what we just created. 03:23.980 --> 03:32.680 So select all from teachers and that is all semicolon at the end. 03:32.680 --> 03:34.480 And go ahead under query. 03:34.750 --> 03:39.010 And you can see we have a teacher's ID I will have the first name right in there. 03:39.010 --> 03:41.050 So we have now to create this table. 03:41.050 --> 03:47.200 And what we need right now is to go ahead and insert some rules into this. 03:47.200 --> 03:52.690 And in creating these rules, we are not going to insert the teacher's ID by ourselves. 03:52.720 --> 03:55.750 Now let's go ahead and remove whatever we have right in there. 03:55.780 --> 03:59.620 Now let's go ahead and insert the rules. 03:59.620 --> 04:05.050 So go ahead and say insert into teachers. 04:05.050 --> 04:06.370 So into the table. 04:06.370 --> 04:10.930 Go ahead and uh insert the values. 04:12.520 --> 04:17.770 And the values I'm going to add is just going to be the first name. 04:18.040 --> 04:18.490 All right. 04:18.490 --> 04:23.880 So and uh I'll go ahead and add. 04:23.910 --> 04:28.650 Let me say, George, why did I add George? 04:28.650 --> 04:32.700 And then if I should put it in, this is going to give you an error. 04:32.730 --> 04:34.050 Let's go ahead and check it out. 04:34.080 --> 04:35.550 We're going to get an error. 04:36.030 --> 04:37.920 We can see down here George. 04:37.950 --> 04:42.720 Column count does not match of value counts at row one. 04:42.720 --> 04:48.000 So you need to specify that you're adding this just to the first name only. 04:48.000 --> 04:51.810 So go right in here and say first underscore name. 04:51.810 --> 04:53.400 And that is it. 04:53.400 --> 04:55.440 So go ahead and execute a query again. 04:55.470 --> 04:57.480 And you can see I have first name George. 04:57.480 --> 05:02.010 And look at it just ID it automatically imputes one. 05:02.010 --> 05:10.290 So if I should go ahead and add Steve and execute this query you can see it just ID incremented to two. 05:10.350 --> 05:18.390 Now if I should continue and add one and then check it out teachers ID three. 05:18.420 --> 05:20.220 And let's go ahead and change the last one. 05:20.220 --> 05:22.290 What we see global. 05:22.290 --> 05:23.430 And um. 05:25.800 --> 05:32.970 Go ahead and Helen is a query to just ID is for so you can know to see how this works. 05:32.970 --> 05:37.650 And the one interesting part of this is that the auto increment can start any way. 05:37.680 --> 05:41.430 Very very interesting path of this auto increment. 05:41.430 --> 05:43.890 So you can actually start from 100. 05:43.920 --> 05:45.120 You can start from ten. 05:45.150 --> 05:46.350 You can start from 20. 05:46.380 --> 05:49.050 You can start from 25 and 18. 05:49.080 --> 05:51.000 Any number of your choice to 1 million. 05:51.000 --> 05:53.370 You can start from 1 million or 1000. 05:53.490 --> 05:58.770 Now let's go ahead and experiment with this and see how that works. 05:58.770 --> 06:03.480 So if I should do that I'll first of all alter the table, go ahead and alter the table and want to 06:03.480 --> 06:06.570 say alter the table. 06:06.570 --> 06:11.910 And the name of the table is a the teachers table. 06:11.940 --> 06:19.230 And if I go ahead I will set auto increment to be equal to any number of I choice. 06:19.260 --> 06:23.700 Let's go ahead and say one dot to be from 100 and put a semicolon at the end. 06:23.730 --> 06:26.250 Now let's go ahead and execute a query. 06:26.250 --> 06:35.550 And down here you can see we set that to 100 Now I'll go ahead and jump this table so I can start afresh. 06:35.580 --> 06:36.060 All right. 06:36.060 --> 06:41.130 So first of all go ahead and delete from. 06:42.840 --> 06:44.490 So delete from teachers. 06:44.490 --> 06:48.600 And if I should delete from teachers I'm going to delete every row. 06:48.630 --> 06:50.310 Go ahead and execute the query. 06:50.310 --> 06:53.760 And now teachers table is now empty again. 06:53.910 --> 07:01.620 So I'll go ahead and insert uh some of the stuff we did previously. 07:01.620 --> 07:07.560 So go ahead and uh, insert uh into teachers. 07:08.340 --> 07:10.260 So go ahead and insert into teachers. 07:10.290 --> 07:15.510 We have already known we're going to put in the first underscore name, because if we don't do that 07:15.510 --> 07:16.920 we're going to get an error. 07:16.920 --> 07:18.600 So the values. 07:21.180 --> 07:27.900 So the values and the semicolon at the end of these. 07:27.900 --> 07:31.650 So let's go ahead and start again with George. 07:32.490 --> 07:41.060 So rest it again with uh so go ahead and start with George and let's go ahead and check it out. 07:41.150 --> 07:42.920 George starts from hundred. 07:43.580 --> 07:44.780 You can see that. 07:44.930 --> 07:49.400 So Steve let's go ahead and execute the query 101. 07:49.730 --> 07:52.130 And now that is interesting. 07:52.160 --> 07:53.540 Go ahead and check it out. 07:54.230 --> 07:59.030 102 and then global. 07:59.030 --> 08:02.840 And that is 103. 08:02.870 --> 08:05.060 So you can see it's very interesting. 08:05.060 --> 08:10.640 And you can start your autoincrement from anywhere to go ahead and alter your table and then begin to 08:10.670 --> 08:14.270 insert your data into your rows. 08:14.270 --> 08:15.950 And it's going to work out fine. 08:15.980 --> 08:18.320 So that is it about Autoincrement. 08:18.320 --> 08:19.790 And I hope that is very interesting. 08:19.790 --> 08:21.620 So play around with it, check it out. 08:21.620 --> 08:25.610 And if you have any question why had I used the question and answer section. 08:25.610 --> 08:28.220 And I'm going to get back to you as soon as possible. 08:28.250 --> 08:29.270 Thank you so much. 08:29.270 --> 08:32.510 And I'm going to see you in the next video lecture.