1 00:00:00,180 --> 00:00:05,050 So as you can see here these are the lines of code that I actually pay said here. 2 00:00:05,250 --> 00:00:09,980 So first of all as you can see I want to actually read some data from the database. 3 00:00:10,020 --> 00:00:10,590 OK. 4 00:00:10,590 --> 00:00:15,540 So as you can see I want to actually get a single computer object from the database and let the data 5 00:00:15,940 --> 00:00:23,190 add here as you can see in lines of 81 through 96 as you can see we have MFX and the access modifiers 6 00:00:23,190 --> 00:00:24,480 of this Smurfit is public. 7 00:00:24,570 --> 00:00:30,660 As you can see here and the return type of dismay for this computer and this means that this method 8 00:00:30,690 --> 00:00:34,190 is going to return an object of type computer. 9 00:00:34,260 --> 00:00:34,850 OK. 10 00:00:35,100 --> 00:00:38,110 And the name of this method is good computer. 11 00:00:38,130 --> 00:00:43,770 So this as you can see here actually accepts an argument of type integer and the name of this argument 12 00:00:43,800 --> 00:00:44,750 is ID. 13 00:00:44,760 --> 00:00:49,310 Now I am actually inside of this method inside the curly braces of this method method. 14 00:00:49,470 --> 00:00:52,650 So let's see what's going on here at the line 83. 15 00:00:52,740 --> 00:00:53,600 As you can see here. 16 00:00:53,820 --> 00:01:01,050 I created an object of type 2 like database and the name of this object is database assignment operator 17 00:01:01,450 --> 00:01:01,960 these. 18 00:01:02,010 --> 00:01:05,300 So this refers to this my is you a late handler class right. 19 00:01:05,480 --> 00:01:07,200 That gets readable database. 20 00:01:07,230 --> 00:01:10,280 So I want you to get the readable database OK. 21 00:01:10,500 --> 00:01:16,050 I want to get the database in order to read the data and I want to assign that database to this database 22 00:01:16,050 --> 00:01:16,440 here. 23 00:01:16,440 --> 00:01:19,190 As you can see here in line 84 here. 24 00:01:19,290 --> 00:01:22,280 I created this up interface here. 25 00:01:22,320 --> 00:01:25,350 As you can see this is actually an interface cursor. 26 00:01:25,470 --> 00:01:25,940 OK. 27 00:01:26,070 --> 00:01:28,180 And here I try to initialized this cursor. 28 00:01:28,320 --> 00:01:33,540 So now let's actually open and documentation and see what is this cursor interface. 29 00:01:33,540 --> 00:01:37,180 So here is the documentation and you can actually enter this. 30 00:01:37,200 --> 00:01:41,570 You are here on your web browser and then you will be guided to this page here. 31 00:01:41,580 --> 00:01:47,880 So this is actually a cursor here and this is an interface and it actually implements this close up 32 00:01:47,880 --> 00:01:49,240 an interface here. 33 00:01:49,290 --> 00:01:56,940 So let's read a description it says this interface provides a random read write access to the result 34 00:01:56,940 --> 00:02:00,140 set returned by your database query. 35 00:02:00,450 --> 00:02:07,280 So by using this a cursor interface I can actually query data from the database. 36 00:02:07,500 --> 00:02:11,370 OK so here I actually created this cursor here. 37 00:02:11,370 --> 00:02:17,850 Assignment operator and then I referred to the name of this database object that query as you can see 38 00:02:17,850 --> 00:02:18,390 here. 39 00:02:18,390 --> 00:02:24,600 Now you want to query data from the database so query these this Meffert this query if it actually accepts 40 00:02:24,600 --> 00:02:25,670 some arguments. 41 00:02:25,830 --> 00:02:29,310 The first argument is actually table computer as you can see here. 42 00:02:29,310 --> 00:02:30,700 This is the table computer. 43 00:02:30,720 --> 00:02:32,310 This is going to be the name of the table. 44 00:02:32,420 --> 00:02:32,950 OK. 45 00:02:33,080 --> 00:02:36,150 That you want to actually get the data up from this database. 46 00:02:36,150 --> 00:02:42,490 So now I want to actually call this method here again in order to show you the arguments. 47 00:02:42,510 --> 00:02:45,170 So database that query. 48 00:02:45,270 --> 00:02:49,950 So the first argument is going to be the table as you can see here strength table. 49 00:02:50,040 --> 00:02:54,290 The second argument is going to be the columns that are inside of that table. 50 00:02:54,390 --> 00:03:01,390 So here as you can see for the second argument I created an object of type upstreams Aure as you can 51 00:03:01,400 --> 00:03:09,030 see for the second argument we need on a string at a which actually includes the columns that are inside 52 00:03:09,030 --> 00:03:09,930 of that table. 53 00:03:09,930 --> 00:03:16,500 So here I created a string Arey object new string ID and inside the curly braces I assigned these objects 54 00:03:16,770 --> 00:03:18,830 that are inside of this at 8. 55 00:03:18,840 --> 00:03:21,600 So that's the first one is column ID. 56 00:03:21,600 --> 00:03:26,760 The second one is going to be column computer name and the third one is going to be Cullom a computer 57 00:03:26,760 --> 00:03:27,340 type. 58 00:03:27,450 --> 00:03:28,500 OK these are the columns. 59 00:03:28,500 --> 00:03:34,260 This is very important for the second argument and for the first argument we need to provide string 60 00:03:34,260 --> 00:03:35,130 selection. 61 00:03:35,130 --> 00:03:41,250 We need to provide a WHERE clause and of classes actually determines how we want to actually get the 62 00:03:41,250 --> 00:03:42,750 data from the database. 63 00:03:42,840 --> 00:03:48,240 For example as you can see here for the first argument which is actually this is actually of type streambed. 64 00:03:48,300 --> 00:03:50,850 And it says its name is selection. 65 00:03:50,850 --> 00:03:56,230 So I want to actually I used to refer to the name of this column column Id plus. 66 00:03:56,250 --> 00:04:00,450 And instead of double quotes on an equal operator here and then a question mark. 67 00:04:00,540 --> 00:04:08,130 And this means all you want to get this specific computer object that is actually related to a specific 68 00:04:08,220 --> 00:04:09,040 ID. 69 00:04:09,390 --> 00:04:15,740 Ok for example I want to actually get the first computer object that its ID is number one. 70 00:04:16,020 --> 00:04:16,420 OK. 71 00:04:16,470 --> 00:04:24,720 So in this way I can I try to get that computed object by providing the ID I can actually get the computer 72 00:04:24,720 --> 00:04:25,160 object. 73 00:04:25,260 --> 00:04:31,860 And that's why I actually specified that this is going to accept an argument of type integer and the 74 00:04:31,860 --> 00:04:34,060 name of this argument is ID. 75 00:04:34,110 --> 00:04:41,250 So by providing an ID for this method I can actually get this specific computed object. 76 00:04:41,250 --> 00:04:43,130 So that's the job of this very close here. 77 00:04:43,140 --> 00:04:48,370 Column ID plus an instead of double quotes like with an equal operator and the question mark. 78 00:04:48,510 --> 00:04:55,680 And this means that by providing an ID for the Smurfit is going to give me the specific computed object 79 00:04:55,680 --> 00:04:57,170 that is related to this ID. 80 00:04:57,360 --> 00:04:58,470 OK. 81 00:04:58,470 --> 00:05:03,880 And here as you can see for the argument here we have this selection artics. 82 00:05:04,040 --> 00:05:04,550 OK. 83 00:05:04,560 --> 00:05:10,410 So we need to actually provide arguments for these of our class here for this fair argument. 84 00:05:10,410 --> 00:05:14,090 So these are the arguments Neal which is actually of type string at a right. 85 00:05:14,130 --> 00:05:19,220 So we need to actually create an object of type string at a new string at a. 86 00:05:19,410 --> 00:05:25,030 And inside the curly braces we need to provide the objects three image that the value of ID the Smurfit 87 00:05:25,240 --> 00:05:31,290 this string that value of method actually accept a value of type integer and then it's going to return 88 00:05:31,350 --> 00:05:33,710 a string value from that integer value. 89 00:05:33,720 --> 00:05:39,930 So this I actually referred to the name of the string class that value of this value of is actually 90 00:05:39,930 --> 00:05:45,760 a static method inside the string class and it's going to accept a value of type integer. 91 00:05:45,780 --> 00:05:51,120 So here I passed this value ID which is actually integer and it's going to convert that value to a string 92 00:05:51,120 --> 00:05:51,960 value. 93 00:05:52,050 --> 00:05:55,610 So it's going to give me the string representation of that idea. 94 00:05:55,940 --> 00:05:56,400 OK. 95 00:05:56,460 --> 00:06:02,350 So this argument this representation of that idea is going to be an argument for this class. 96 00:06:02,490 --> 00:06:06,210 Yet as you can see Klallam Plus the equal operator question. 97 00:06:06,480 --> 00:06:08,830 This is going to be an argument for this one. 98 00:06:08,880 --> 00:06:15,210 And this means I want to actually get the ID that it's related to a specific computer object and I want 99 00:06:15,210 --> 00:06:17,460 to return that computer object. 100 00:06:17,720 --> 00:06:18,350 OK. 101 00:06:18,720 --> 00:06:24,510 And here for for these arguments I assigned the value for example for this group by having an order 102 00:06:24,510 --> 00:06:24,870 by. 103 00:06:24,960 --> 00:06:25,830 OK. 104 00:06:26,000 --> 00:06:28,470 Are you saying that value not because we don't need them. 105 00:06:28,470 --> 00:06:32,290 And here at the end of my statement I actually put a semicolon. 106 00:06:32,510 --> 00:06:33,020 OK. 107 00:06:33,120 --> 00:06:40,260 So in actuality this line of code here and here I created an if statement here and it's as if cursor 108 00:06:40,920 --> 00:06:45,650 this cursor here as you can see this interface as you can see here is not equal to null. 109 00:06:45,900 --> 00:06:48,290 OK cursor move to first. 110 00:06:48,360 --> 00:06:55,490 So this means that if we actually have some optics inside our database OK and we can actually read those 111 00:06:55,500 --> 00:07:00,630 data then it's going to go to their first object inside the database. 112 00:07:00,630 --> 00:07:02,060 Inside it is like database. 113 00:07:02,070 --> 00:07:06,980 If the cursor is equal to null then it's not going to actually go inside the database and read the data 114 00:07:07,020 --> 00:07:09,200 because we don't have data in our database. 115 00:07:09,390 --> 00:07:10,850 OK so this has been important. 116 00:07:11,310 --> 00:07:16,160 And in light 93 here I created an object of type computer. 117 00:07:16,230 --> 00:07:19,850 So tell me about this if it is going to return an update of the computer. 118 00:07:19,850 --> 00:07:26,070 If we pass the ID to the Smurfette and then it's going to return an object that is actually specific 119 00:07:26,070 --> 00:07:30,340 to that ID and then we can actually get that computed object. 120 00:07:30,420 --> 00:07:35,370 So in 93 I created an object of type computer assignment operator. 121 00:07:35,520 --> 00:07:39,350 And here I actually initialize this computer Optix new computer. 122 00:07:39,690 --> 00:07:45,620 So here we are actually providing free arguments for the constructor of this computer class. 123 00:07:45,840 --> 00:07:52,050 So inside this computer class remember that you had three constructors as you can see here and here 124 00:07:52,070 --> 00:07:54,140 in say this is tool like handler class. 125 00:07:54,240 --> 00:08:01,170 I want to call this one constructor that that actually accepts free arguments which is the computer 126 00:08:01,170 --> 00:08:02,850 name and computer type. 127 00:08:02,850 --> 00:08:05,790 So here as you can see new computer. 128 00:08:05,940 --> 00:08:08,480 And for the first argument we need to provide the ID. 129 00:08:08,550 --> 00:08:12,010 So I called this integer class data parsing. 130 00:08:12,030 --> 00:08:16,490 So this is going to accept a string value and then it's going to convert. 131 00:08:16,500 --> 00:08:20,160 That's why the gateway integer value so integer that parse. 132 00:08:20,550 --> 00:08:26,040 And for the argument of this parsing in Smurfette you refer to the name of this cursor object as you 133 00:08:26,040 --> 00:08:28,240 can see here cursor that get strange. 134 00:08:28,290 --> 00:08:33,990 So it's going to get this string representation of the first column the first column is actually column 135 00:08:33,990 --> 00:08:34,550 Id. 136 00:08:34,650 --> 00:08:35,630 As you can see here. 137 00:08:35,850 --> 00:08:38,940 So it's going to give me that string representation of that ID. 138 00:08:39,030 --> 00:08:39,450 OK. 139 00:08:39,570 --> 00:08:41,990 Which is going to be an integer value. 140 00:08:42,060 --> 00:08:46,920 So it's going to dismiss that person is going on is going to convert that's by the value to the integer 141 00:08:46,920 --> 00:08:47,700 value. 142 00:08:47,700 --> 00:08:53,040 And then we can actually put that's about you as the id of the constructor and for the second argument 143 00:08:53,190 --> 00:08:55,380 we need to think about your computer name. 144 00:08:55,380 --> 00:09:01,170 So inside this computer class as you can see for the second value of the second argument we need a string 145 00:09:01,190 --> 00:09:06,830 value computer name and for the first argument we need a string value again for the for the first argument. 146 00:09:06,840 --> 00:09:09,630 OK so this is the second argument as you can see here. 147 00:09:09,630 --> 00:09:10,670 String computer. 148 00:09:10,830 --> 00:09:12,390 And this is the first argument. 149 00:09:12,390 --> 00:09:17,520 So if you say this is like handler class for the second argument cursor that get string 1. 150 00:09:17,610 --> 00:09:23,940 This one refers to the Cullom computer name and for the first argument as you can see here cursor that 151 00:09:23,940 --> 00:09:28,390 gets Turing to these two refers to the current computer type. 152 00:09:28,620 --> 00:09:33,330 OK so I want to get these data and then assign those data to the computer object. 153 00:09:33,330 --> 00:09:38,470 And at the end in 95 I want to actually return this computer object from dismiss it. 154 00:09:38,700 --> 00:09:39,720 OK. 155 00:09:39,720 --> 00:09:41,290 So hopefully that makes sense. 156 00:09:41,370 --> 00:09:46,560 And now I'm going to paste in some other method here and then I'm going explain to you what's going 157 00:09:46,560 --> 00:09:47,200 on here.