1 00:00:00,350 --> 00:00:03,360 So the access modify it is public as you can see here. 2 00:00:03,630 --> 00:00:08,870 And the name of the constructor must be the same as the name of our class. 3 00:00:08,870 --> 00:00:14,070 So I just know that type been here my school like handler and inside apprentices I need to provide an 4 00:00:14,130 --> 00:00:17,610 argument of type context as you can see here. 5 00:00:17,900 --> 00:00:23,030 And the name of this argument is going to be context and that I need to open and close this constructor 6 00:00:23,040 --> 00:00:24,860 by using these curly braces. 7 00:00:25,050 --> 00:00:30,720 And here as you can see we have an error and this error is because of the constructor of the superclass. 8 00:00:30,750 --> 00:00:34,990 So we need to actually call the constructor of the superclass. 9 00:00:34,980 --> 00:00:38,960 So I just need to type in here super at inside Apprentice's. 10 00:00:39,150 --> 00:00:41,530 I need to provide some values. 11 00:00:41,580 --> 00:00:50,070 The first value that I need to provide here is actually context comma and the second argument that I 12 00:00:50,070 --> 00:00:52,550 need to provide is actually the name of the database. 13 00:00:52,560 --> 00:00:54,890 So here I just need to type in database name. 14 00:00:55,020 --> 00:01:00,720 So here I actually fell to the name of these constants that I actually created in line 17 as you can 15 00:01:00,720 --> 00:01:01,480 see here. 16 00:01:01,530 --> 00:01:05,070 I specified the name of the database so computer that. 17 00:01:05,090 --> 00:01:06,820 This is the name of my database right. 18 00:01:06,990 --> 00:01:11,580 So for the second argument I need to provide the database name karma. 19 00:01:12,110 --> 00:01:15,140 And for the first argument I assign the value null. 20 00:01:15,150 --> 00:01:18,450 So let's actually hold the command key and then click on the super here. 21 00:01:18,450 --> 00:01:21,600 So if you are using I mean those machine just hold the control key. 22 00:01:21,600 --> 00:01:23,340 And then click on the super here. 23 00:01:23,520 --> 00:01:28,800 And as you can see here we have these a constructor here and this constructed here. 24 00:01:28,830 --> 00:01:34,350 So as you can see here we are actually calling this a first constructor. 25 00:01:34,440 --> 00:01:38,400 This first constructed of the superclass is q like open helper. 26 00:01:38,400 --> 00:01:40,020 The first one is context. 27 00:01:40,080 --> 00:01:42,540 The second one the name of the database. 28 00:01:42,600 --> 00:01:46,020 OK database name and the first one is cursor factory. 29 00:01:46,020 --> 00:01:51,910 So for the cursor factory I assigned the value not because we don't need a cursor factory for this application. 30 00:01:52,070 --> 00:01:52,710 OK. 31 00:01:52,980 --> 00:01:57,470 And for the first argument we need to actually provide the database version. 32 00:01:57,660 --> 00:02:03,810 OK so here as you can see for the first argument which is actually across a factory which we don't need 33 00:02:03,810 --> 00:02:10,740 that in the application I assign the value null and I put a comma here and there for the fourth argument 34 00:02:10,770 --> 00:02:13,320 I assigned the value database version. 35 00:02:13,320 --> 00:02:16,450 So here I need to specify the version of the database. 36 00:02:16,470 --> 00:02:19,110 So as you can see here the error is gone. 37 00:02:19,110 --> 00:02:20,020 Right. 38 00:02:20,040 --> 00:02:26,010 So now I need to actually overwrite some of the methods that are actually inside of this is like open 39 00:02:26,010 --> 00:02:26,940 helper class. 40 00:02:27,060 --> 00:02:33,750 And as you can see here it says class is school that handler must be declared abstract or implement 41 00:02:33,810 --> 00:02:38,180 abstract method of great and the uncreate in a school like open helper. 42 00:02:38,370 --> 00:02:43,920 So here as you can see we've got two methods that we need to actually override here inside our school 43 00:02:43,920 --> 00:02:45,240 like handler class. 44 00:02:45,240 --> 00:02:51,240 The first one is actually uncreate and if it says this is the method that we need to provide for this 45 00:02:51,690 --> 00:02:53,290 why is q late handler class. 46 00:02:53,310 --> 00:02:56,210 So as you can see here is the name of this method is uncreate. 47 00:02:56,220 --> 00:03:01,050 And as you can see this if it actually to accept an argument which is of type A school like database 48 00:03:01,110 --> 00:03:03,400 and the name of this argument is the B. 49 00:03:03,570 --> 00:03:09,650 So here inside the Smurfit I can just refer to the name of this db here D-B argument which is of type 50 00:03:09,660 --> 00:03:16,500 as school database that executes execute as well as you can see here and here in say the practice of 51 00:03:16,500 --> 00:03:16,980 this method. 52 00:03:16,990 --> 00:03:19,970 I can just refer to the name of this string valuable. 53 00:03:19,980 --> 00:03:24,690 Create a computer table create computer table. 54 00:03:24,900 --> 00:03:29,250 OK so now it can actually create a computer table for us. 55 00:03:29,340 --> 00:03:31,920 OK for this application this is really important. 56 00:03:31,920 --> 00:03:33,590 You need to put this value here. 57 00:03:33,690 --> 00:03:34,240 OK. 58 00:03:34,260 --> 00:03:37,920 Otherwise it's not going to actually create a table for our application. 59 00:03:37,920 --> 00:03:38,480 OK. 60 00:03:38,850 --> 00:03:46,490 So now I need to overwrite the upgrade Smurfette upgrade here and this method is going to be called. 61 00:03:46,740 --> 00:03:51,930 For example when you happen when you actually upload or your application to the Google Play store and 62 00:03:52,090 --> 00:03:57,920 venue and for example two months later you want to update your application and you want to actually 63 00:03:57,930 --> 00:03:59,690 change your database. 64 00:03:59,700 --> 00:04:01,880 This limit is for that situation. 65 00:04:02,070 --> 00:04:07,910 So you need to actually drop the current database and then create a new database. 66 00:04:08,010 --> 00:04:13,080 OK so now I'm going to paste in some lines of code here and then I'm going explain to you what's going 67 00:04:13,080 --> 00:04:13,850 on here. 68 00:04:13,860 --> 00:04:20,000 So as you can see here these are the lines of code that I actually pasted here inside this on upgrade 69 00:04:20,010 --> 00:04:20,640 Befort. 70 00:04:20,850 --> 00:04:26,030 And as you can see ighly further to the name of this argument which is of type Escuela database db that 71 00:04:26,100 --> 00:04:30,600 execute as well as you can see here and inside the double quotes. 72 00:04:30,600 --> 00:04:32,790 I just typed in our drop table. 73 00:04:32,820 --> 00:04:33,890 If exists. 74 00:04:34,060 --> 00:04:34,590 OK. 75 00:04:34,800 --> 00:04:38,600 And then here I put a space here plus table computer. 76 00:04:38,610 --> 00:04:44,600 So here I refer to my table computer and as you can see here we've got other arguments. 77 00:04:44,610 --> 00:04:48,900 The old version this old version means the old version of our database. 78 00:04:49,050 --> 00:04:52,320 And this new version means that the new version of our database. 79 00:04:52,320 --> 00:04:55,490 So as you can see here the old version as you can see is one. 80 00:04:55,590 --> 00:04:55,980 OK. 81 00:04:56,010 --> 00:05:00,930 Our current database version is one and if you want to update this application that and add another 82 00:05:00,930 --> 00:05:08,010 database to this application of the old version is going to be dropped here dropped drop believe exists. 83 00:05:08,160 --> 00:05:10,780 And the new version is going to be used instead. 84 00:05:10,950 --> 00:05:17,310 So as you can see here in line 50 free eyechart this uncreate D-B effort in order to create a new database. 85 00:05:17,310 --> 00:05:18,830 So hopefully that makes sense. 86 00:05:18,990 --> 00:05:21,280 But for this application we don't use. 87 00:05:21,410 --> 00:05:25,610 We don't actually need this Meffert but we need to actually write this method. 88 00:05:25,620 --> 00:05:28,940 Here are my escalate handler class. 89 00:05:28,950 --> 00:05:29,820 OK. 90 00:05:29,970 --> 00:05:31,430 So hopefully that makes sense. 91 00:05:31,590 --> 00:05:37,980 And now inside this class inside this school that handler class I need to actually provide some operations 92 00:05:38,010 --> 00:05:44,940 some efforts in order to for example add a computer object to the database or for example a deletes 93 00:05:45,000 --> 00:05:51,630 a computer object from the database or for example get all the objects that are inside the database 94 00:05:51,900 --> 00:05:55,160 and put them in for example in an other place. 95 00:05:55,170 --> 00:06:00,120 So here I'm going to actually pasting those methods and then I'm going explain to you what's going on 96 00:06:00,120 --> 00:06:00,650 here. 97 00:06:00,660 --> 00:06:07,530 So as you can see here these are the lines of code that I actually pasted here and in 9:59 as you can 98 00:06:07,530 --> 00:06:15,880 see I created a comment here and it says all database operations create Leatt update and delete as you 99 00:06:15,890 --> 00:06:16,900 can see here. 100 00:06:16,920 --> 00:06:23,250 So here the first of Meffert is going to actually create an object and then it's going to add that updating 101 00:06:23,250 --> 00:06:25,570 to the database into the database. 102 00:06:25,710 --> 00:06:29,500 OK so then those data are going to be saved. 103 00:06:29,690 --> 00:06:33,010 And we can access that data of what we want. 104 00:06:33,030 --> 00:06:33,490 OK. 105 00:06:33,600 --> 00:06:39,530 So the first one is create And as again see to the Access modify it of the Smif it is public. 106 00:06:39,570 --> 00:06:44,760 The return type of this method is void and this means that this is going to return Nuffield and the 107 00:06:44,760 --> 00:06:46,670 name of this method is at computer. 108 00:06:46,800 --> 00:06:51,270 So it's going to add the computer into the database and this it actually to access an argument of type 109 00:06:51,270 --> 00:06:57,000 computer as you can see we have a computer class inside our project and as you can see these are the 110 00:06:57,000 --> 00:07:02,620 instance variables and we've got the constructors and the getters and setters for our instance Friday. 111 00:07:02,910 --> 00:07:07,410 So I want to create a computer objects and put those objects into that database. 112 00:07:07,410 --> 00:07:08,280 Right. 113 00:07:08,280 --> 00:07:15,240 So the first one is going to do that creation for me at the computer and inline 64 inside the Smurfit. 114 00:07:15,360 --> 00:07:16,900 Let's see what's going on here. 115 00:07:16,920 --> 00:07:23,040 The first method the first actually the first line of code inside the sniffer is actually creating an 116 00:07:23,130 --> 00:07:26,270 object of type as it's like database. 117 00:07:26,280 --> 00:07:29,170 OK so here I want to access the Kulik database. 118 00:07:29,190 --> 00:07:29,730 OK. 119 00:07:29,980 --> 00:07:33,850 Is Q Like database and the name of this object is database. 120 00:07:33,900 --> 00:07:35,600 So I want to access the database right. 121 00:07:35,730 --> 00:07:37,370 Assignment operator. 122 00:07:37,590 --> 00:07:43,720 So here I am actually referring to the name of my to the name of this class. 123 00:07:43,750 --> 00:07:45,340 It is too late handler class. 124 00:07:45,360 --> 00:07:46,230 This is very important. 125 00:07:46,230 --> 00:07:48,960 You need to refer to the name of this class. 126 00:07:49,000 --> 00:07:54,660 It is too late handler class that does not get rewriteable database. 127 00:07:54,840 --> 00:07:58,080 So here I want to actually get the right level. 128 00:07:58,110 --> 00:08:01,950 And this means that all you want to actually add some data. 129 00:08:02,190 --> 00:08:07,060 I want to write some data into the database so I need to get the right get the right abilities. 130 00:08:07,170 --> 00:08:11,850 If you've got an other method and its name is get a readable database and this method and that if it 131 00:08:11,850 --> 00:08:15,360 is going to be used whenever you want to actually read some data in the database. 132 00:08:15,450 --> 00:08:19,240 But here I want to add an object of type computer into the database. 133 00:08:19,320 --> 00:08:24,930 So I need to get this get a little bit database here like table database is very important for dismiss 134 00:08:24,930 --> 00:08:25,180 it. 135 00:08:25,260 --> 00:08:25,920 OK. 136 00:08:26,280 --> 00:08:32,340 I could actually get it at this my Estulin handler class and then instead of this this here is actually 137 00:08:32,340 --> 00:08:32,750 enough. 138 00:08:32,760 --> 00:08:33,100 OK. 139 00:08:33,120 --> 00:08:35,650 These that get the right ability. 140 00:08:35,850 --> 00:08:40,230 So this up this keyboard actually refers to the name of this class. 141 00:08:40,300 --> 00:08:47,790 Is your late handler so as you can see in sixty 65 I created another object and the name of this object 142 00:08:47,790 --> 00:08:49,460 is content values. 143 00:08:49,680 --> 00:08:55,310 And as you can see I assigned a value on a values for the name of this object. 144 00:08:55,320 --> 00:08:56,050 OK. 145 00:08:56,160 --> 00:09:00,250 Values assignment operator new contents values. 146 00:09:00,270 --> 00:09:06,120 So here I created an object and its name is values which is actually of type content values. 147 00:09:06,240 --> 00:09:06,770 OK. 148 00:09:06,960 --> 00:09:10,380 So let's see how we can use this object in line 66. 149 00:09:10,470 --> 00:09:14,560 I refer to the name of this values object that puts. 150 00:09:14,610 --> 00:09:18,470 So you want to actually put some data into these values right. 151 00:09:18,510 --> 00:09:21,510 So values that puts Cullom computer name. 152 00:09:21,510 --> 00:09:24,240 So the first argument is going to be the Cullom. 153 00:09:24,240 --> 00:09:29,770 So for the Cullom computer name you want to assign the value computer that gets a computer name. 154 00:09:29,910 --> 00:09:36,100 You want to assign a value computer name for this column Cullom computer name and inline 6 to 7. 155 00:09:36,100 --> 00:09:39,380 Again I actually refer to the name of this values object that pute. 156 00:09:39,600 --> 00:09:42,050 So I want to assign a value to these values right. 157 00:09:42,090 --> 00:09:45,090 So values that puts Cullom computer type. 158 00:09:45,140 --> 00:09:50,610 So for this color I want to assign the value computer as you can see I am referring to the name of this 159 00:09:50,670 --> 00:09:51,720 argument right. 160 00:09:51,750 --> 00:09:54,070 Computers that gets computer type. 161 00:09:54,420 --> 00:09:54,660 OK. 162 00:09:54,720 --> 00:10:00,770 In this way I am actually getting the computer and the computer type and then inlight 69 as you can 163 00:10:00,770 --> 00:10:08,340 see I refer to the name of this database object that I actually did it created inline 64 database that 164 00:10:08,440 --> 00:10:09,500 in there. 165 00:10:09,920 --> 00:10:14,010 As you can see this effort is going to actually accept the arguments. 166 00:10:14,030 --> 00:10:16,430 The first one is table computer. 167 00:10:16,490 --> 00:10:18,330 This is the name of the table. 168 00:10:18,350 --> 00:10:24,560 So if you want to actually put those data up the date of the computer object into this table computer 169 00:10:24,560 --> 00:10:25,080 right. 170 00:10:25,090 --> 00:10:26,340 So table a computer. 171 00:10:26,360 --> 00:10:28,200 The second argument is null. 172 00:10:28,460 --> 00:10:34,840 OK so now let me actually call this method here again database that inserts and as you can see here. 173 00:10:34,970 --> 00:10:37,240 Does this mean for you to access the argument. 174 00:10:37,340 --> 00:10:40,010 The first one is table which we actually assign here. 175 00:10:40,100 --> 00:10:46,060 And the second one is gnarl column Hach which we don't actually use that in our application. 176 00:10:46,160 --> 00:10:51,990 And the first one is values which is actually of type content values that be created in line 65. 177 00:10:52,190 --> 00:10:57,600 OK so let me read this line of code here and here as you can see for the first argument I actually assigned 178 00:10:57,600 --> 00:10:59,840 a value of values here as you can see. 179 00:11:00,110 --> 00:11:08,360 So here I actually inserted these values into their database and in line 70 72 I need to actually close 180 00:11:08,360 --> 00:11:11,020 this database so the database that close. 181 00:11:11,360 --> 00:11:13,060 So hopefully that makes sense. 182 00:11:13,170 --> 00:11:18,320 And now I'm going to paste another method here and then I'm going to explain to you what's going on 183 00:11:18,320 --> 00:11:18,760 here.