1 00:00:02,280 --> 00:00:05,250 So in this session we are going to learn about Redis sets. 2 00:00:05,840 --> 00:00:13,650 So sets are basically unordered collection of strings and it supports operation such as adding and removing 3 00:00:13,830 --> 00:00:18,540 or checking existence of the members which are a part of a set. 4 00:00:21,350 --> 00:00:23,190 if you talk about the feature of Sets. 5 00:00:23,210 --> 00:00:26,810 So basically Set doesn't allow us to repeat the members. 6 00:00:26,810 --> 00:00:32,470 So if you have same members stored in the set once, then you won't be allowed to store the same 7 00:00:32,470 --> 00:00:36,240 number again and about the use case. 8 00:00:36,240 --> 00:00:37,270 Okay. 9 00:00:37,410 --> 00:00:44,730 This you can use if you want to see like unique visitors of your Web site or if you want to store like 10 00:00:44,730 --> 00:00:45,450 top 5 11 00:00:46,110 --> 00:00:54,500 You know, top 5 winners, or those kind of use cases. You can use Sets. So let's begin with some example. 12 00:00:54,540 --> 00:00:59,440 So let me check if I already have something, I already have some data stored.So 13 00:00:59,460 --> 00:01:08,390 I'm going to flush everything and now we are going to begin from the fresh. Okay. 14 00:01:08,400 --> 00:01:15,120 So first thing I'm going to tell you how we can add the member of or how we can add a member in the 15 00:01:15,120 --> 00:01:16,290 sets. 16 00:01:16,350 --> 00:01:20,870 So you need to you sadd command and you need to provide a key name. 17 00:01:20,880 --> 00:01:30,430 So in this case, let's say we want to store all the visitors of our website. So I'll give the key name 18 00:01:30,430 --> 00:01:38,050 as user's IP and then we'll be storing IP addresses of the visitors. So to store one member, you can just 19 00:01:38,050 --> 00:01:43,990 type 1 IP and hit enter. If you want to store multiple members, you can provide multiple members 20 00:01:44,110 --> 00:01:45,340 separated by space 21 00:01:51,800 --> 00:01:53,410 similar to this one. 22 00:01:53,420 --> 00:01:58,850 So now if you want to see total number of members available in this list. 23 00:01:58,850 --> 00:02:02,390 So for that one we have a command which is called cardinality. 24 00:02:03,560 --> 00:02:08,690 So scard card is going to tell you, the total number of members available in this set. 25 00:02:09,590 --> 00:02:11,770 So let's run scard 26 00:02:11,900 --> 00:02:14,600 And then you need to provide the key name. 27 00:02:14,690 --> 00:02:20,040 Also you can see that Redis client is giving you a hint that you need to provide Key Name. 28 00:02:20,150 --> 00:02:28,190 So once we do that and hit enter. We can see that there are total 4 members available in this key. 29 00:02:28,190 --> 00:02:32,060 So one of the member we added here and then we added another 3 members here. 30 00:02:32,600 --> 00:02:35,960 So it is giving us the correct count. 31 00:02:36,020 --> 00:02:40,960 Now let's say we want to see a list of all the members which are stored in this set. 32 00:02:41,030 --> 00:02:45,590 So for that command is smembers and you need to provide the key name. 33 00:02:48,700 --> 00:02:53,700 Hit enter and then you'll be able to see all the members, which are part of this key 34 00:02:57,920 --> 00:03:04,200 Now let's say if you want to see or you want to do kind of comparison between yesterday's visitors and 35 00:03:04,200 --> 00:03:05,100 today's visitor. 36 00:03:05,760 --> 00:03:10,850 So we have a command which is called s difference or s diff. 37 00:03:10,860 --> 00:03:16,760 Basically that's going to give you a difference between members of two keys. 38 00:03:17,480 --> 00:03:19,470 So let me show you by example. 39 00:03:19,610 --> 00:03:26,270 So let's say we have users IP which stores visitors of today and then we have another key which is called 40 00:03:27,320 --> 00:03:30,760 previous IP. 41 00:03:30,760 --> 00:03:36,820 This is the one which is going to store IP addresses of the members who visited previously or let's say who 42 00:03:36,820 --> 00:03:42,680 visited yesterday. So let's rather just make it Yesterday Visit. 43 00:03:47,580 --> 00:03:55,180 I'm just going to call it Yesterday IP and then let's say there was user 10.0. 0.1 44 00:03:55,230 --> 00:04:00,950 So this is a visitor, who visited yesterday also and then we have another visitors which is 45 00:04:01,010 --> 00:04:04,090 192.168. 0 46 00:04:04,110 --> 00:04:13,130 This is another visitor who had visited yesterday and then we also had some more visitors like with the 47 00:04:13,150 --> 00:04:19,010 IP of this and I'm just going to add couple of more's 48 00:04:23,920 --> 00:04:25,960 Hit enter and now let's see 49 00:04:25,960 --> 00:04:27,850 all the members in this key. 50 00:04:33,630 --> 00:04:33,930 okay. 51 00:04:33,940 --> 00:04:36,070 So these are our yesterday's visitors. 52 00:04:36,070 --> 00:04:39,450 And then these are the one's which are over today's visitor. 53 00:04:39,840 --> 00:04:46,630 And now if we want to see the difference between yesterday's visitors and today's visitor we can do 54 00:04:47,980 --> 00:04:49,110 sdiff 55 00:04:49,370 --> 00:05:00,170 So I'm going to do sdiff and then let's do a difference between users IP. 56 00:05:00,170 --> 00:05:03,280 This is the one which is keeping our today's visitor 57 00:05:03,470 --> 00:05:04,970 And then we have yesterday's IP. 58 00:05:04,970 --> 00:05:07,580 This is the one which is keeping yesterday's visitor. 59 00:05:07,820 --> 00:05:12,440 So once we hit enter. We are getting only 2 members. 60 00:05:12,460 --> 00:05:12,720 OK. 61 00:05:12,760 --> 00:05:21,120 So these are the members or you can say these are the members which were, which visited yesterday but 62 00:05:21,120 --> 00:05:24,060 did not visit today. Okay. 63 00:05:24,100 --> 00:05:29,770 Or if you want to see which are the members which visited today only and which had not visited yesterday. 64 00:05:29,770 --> 00:05:36,820 In that case you need to type sdiff and you need to provide yesterday's IP and then you need to 65 00:05:36,820 --> 00:05:39,540 provide today's. 66 00:05:39,790 --> 00:05:45,930 And now this is going to give you only the users, who have visited today but have not visited yesterday. 67 00:05:54,090 --> 00:06:00,760 Now let's say you want to see whether one of the member exists or already exist in a set or not. 68 00:06:00,810 --> 00:06:06,960 In that case, you use command which is called S is member. 69 00:06:07,290 --> 00:06:13,530 So we have sismember command which is going to give you, or going to check basically the existence 70 00:06:13,590 --> 00:06:21,500 of a specific member. So as we know, we have a key which is yesterday IP and we have added one of the 71 00:06:21,500 --> 00:06:23,750 members with this IP. 72 00:06:23,750 --> 00:06:30,470 So I'm just going to copy and paste that and then if wehit enter, we are going to get a reply of 1 73 00:06:30,470 --> 00:06:35,920 which means that this member is already part of this Set. 74 00:06:35,960 --> 00:06:39,530 Now let's say if I give some different IP which doesn't exist 75 00:06:44,070 --> 00:06:50,310 and if I hit enter this time I get a reply of 0, which means this member is not part of the Set. 76 00:06:53,400 --> 00:06:56,310 So you can use it for Use Cases, like if you want to see that 77 00:06:56,500 --> 00:07:00,560 this member already visited our website today or it doesn't visit. 78 00:07:00,750 --> 00:07:07,290 So you can use it for those kind of Use Cases and then you can show some promo to the user who hasn't 79 00:07:07,290 --> 00:07:10,770 visited or who has visited this website for the first time 80 00:07:15,440 --> 00:07:22,190 and now we are going to discuss about moving one of the members from one list or one Set to another 81 00:07:22,190 --> 00:07:22,460 Set. 82 00:07:26,390 --> 00:07:33,170 So the command for that is smove and now as soon as I type smove, you can see that it is giving me 83 00:07:33,190 --> 00:07:38,700 hint that I need to provide Source and Destination and also the Member which I want to move. 84 00:07:39,600 --> 00:07:48,440 So let's say I want to move from yesterday IP, I want to move to a new key which is called, 85 00:07:53,220 --> 00:07:57,890 let's call it previous IP. 86 00:07:58,170 --> 00:07:58,590 Okay. 87 00:07:58,590 --> 00:08:06,660 And we want to move a member which is having IP address of 192.168.0 88 00:08:06,670 --> 00:08:08,020 Now once we hit enter 89 00:08:12,230 --> 00:08:14,950 one sec and let me adjust this. 90 00:08:19,680 --> 00:08:20,280 okay. 91 00:08:20,330 --> 00:08:21,950 So now you can see. 92 00:08:21,950 --> 00:08:28,700 So once we hit enter we can see we got a response of 1, which means that it has moved this member from 93 00:08:29,830 --> 00:08:32,090 yesterday IP to previous IP key. 94 00:08:32,110 --> 00:08:37,570 And remember if the key doesn't exist. Redis is going to create that key. 95 00:08:37,570 --> 00:08:39,790 So previous IP was not existing. 96 00:08:39,790 --> 00:08:47,910 So Redis created a new key and also assigned or moved this member from yesterday IP to previous IP. 97 00:08:48,040 --> 00:08:58,070 So let's see members of previous IP and now we can see we have this member added in this new key. 98 00:08:58,070 --> 00:09:04,460 Now let's say if the key only exists and if we want to move another member, then what's going to happen? 99 00:09:09,970 --> 00:09:15,070 So I'm going to move another member with IP of this 100 00:09:20,490 --> 00:09:22,980 and this is the Key where we want to move this member. 101 00:09:23,760 --> 00:09:24,030 Okay. 102 00:09:24,030 --> 00:09:26,940 So hit enter and you get a response of 1 103 00:09:26,970 --> 00:09:27,210 Okay. 104 00:09:27,210 --> 00:09:30,240 So the key was already existing. Redis knew it. 105 00:09:30,300 --> 00:09:40,050 And so it has just added the member to that set. So now if we do smembers again then we are getting 106 00:09:40,050 --> 00:09:41,820 the response with 2 members 107 00:09:47,110 --> 00:09:56,590 and now let's talk about removing one of the members from the Set. So for removing, we have two commands 108 00:09:56,590 --> 00:09:58,970 one command is s Pop. 109 00:09:58,990 --> 00:10:07,040 So what s Pop is going to do is, it is going to remove one of the random members and if you want to remove 110 00:10:07,100 --> 00:10:13,680 some specific member, then we have a command which is called s remove and short form is srem. 111 00:10:13,700 --> 00:10:16,050 This is a command which you need to use. 112 00:10:16,070 --> 00:10:20,600 So let's clear the screen first and I'm going to add few members 113 00:10:24,220 --> 00:10:26,980 in our key, which is called Users. 114 00:10:26,980 --> 00:10:28,300 And let me add few names 115 00:10:35,180 --> 00:10:36,630 and hit enter. 116 00:10:36,710 --> 00:10:39,380 Let's check the members by using smembers command. 117 00:10:43,260 --> 00:10:45,300 I just typed the commands incorrectly. 118 00:10:45,300 --> 00:10:52,380 So we have to type smembers and the Key Name, which is users and now we see all the members which are added 119 00:10:52,380 --> 00:10:52,530 here. 120 00:10:52,560 --> 00:10:57,100 So here if i do spop, it is going to randomly remove one of the user. 121 00:11:03,750 --> 00:11:04,310 okay. 122 00:11:05,500 --> 00:11:07,330 And let's see s members again 123 00:11:11,640 --> 00:11:11,950 OK. 124 00:11:11,990 --> 00:11:20,320 So once we see this users Set again. Now we can see we have only 4 members which are remaining in 125 00:11:20,320 --> 00:11:28,610 this Set. Now let's say rather than 1, if you want to remove 2 or 3 members or any number of members 126 00:11:28,670 --> 00:11:29,840 out of this list. 127 00:11:29,840 --> 00:11:35,510 So in that case you can use spop. So guys, if I'm saying List, 128 00:11:35,510 --> 00:11:39,080 So basically I'm just talking about Set, in this session. 129 00:11:39,080 --> 00:11:48,010 So do not confuse it with List command, which is a separate you know, separate Data type. Okay, because by 130 00:11:48,010 --> 00:11:52,440 List, I just mean is Listing of these members. Okay. 131 00:11:52,450 --> 00:11:56,480 So basically in today's session, it is all about Sets and Sets Data Type. 132 00:11:56,550 --> 00:11:58,360 Okay. 133 00:11:58,390 --> 00:12:01,720 So, let's say I want to remove multiple members from this Sets. 134 00:12:01,750 --> 00:12:07,870 So in that case I need to use spop and I need to give the key name which is Users and then we need 135 00:12:07,870 --> 00:12:11,050 to give the Number of members which we want to remove. 136 00:12:11,050 --> 00:12:19,390 So in this case, if I give 2, it is going to remove 2 members from this set. OK. 137 00:12:19,400 --> 00:12:26,600 So it has removed these 2 members randomly and you cannot decide which is the member which you want 138 00:12:26,600 --> 00:12:27,050 to remove. 139 00:12:27,050 --> 00:12:32,980 So it's just going to remove 2 members randomly and now let's see the list again. 140 00:12:39,430 --> 00:12:40,010 OK. 141 00:12:40,160 --> 00:12:46,400 So now we can see, this is the, these are the members which we have in our users Set. 142 00:12:55,020 --> 00:13:02,540 and now I'm going to add few more members again and notice I'm just copy pasting the same command, 143 00:13:02,540 --> 00:13:04,400 which we had added previously. 144 00:13:04,400 --> 00:13:10,820 So in this case, you can see we already have members like John and Martin in this set. 145 00:13:11,360 --> 00:13:16,540 However, once we try to Edit again basically it is just going to ignore these members. 146 00:13:16,610 --> 00:13:23,900 So let's hit enter and we see, we have 3 items added because 2 users name which are called John 147 00:13:23,900 --> 00:13:25,340 and Martin were already there. 148 00:13:25,370 --> 00:13:35,650 So it just added 3 more members and let's see the Sets by using smembers. 149 00:13:35,810 --> 00:13:41,330 So now we can say these are the members which we have. Now let's say, if I want to remove some specific 150 00:13:41,330 --> 00:13:44,750 member. Let's say in this case, I want to remove John. 151 00:13:45,230 --> 00:13:48,980 So in that case, I need to use srem command. 152 00:13:48,980 --> 00:13:55,630 So this is shortform for Remove, and then you need to provide the Key Name and then you need to provide 153 00:13:55,630 --> 00:14:01,610 the Member Name. If you want to remove Multiple Members, you can provide multiple members you need to 154 00:14:01,610 --> 00:14:04,140 separate all the members by a space. 155 00:14:04,160 --> 00:14:08,690 So in this case let's remove 1 member and let's check the Sets again. 156 00:14:11,800 --> 00:14:12,330 OK. 157 00:14:12,360 --> 00:14:15,270 And now let's remove couple of more members. 158 00:14:19,690 --> 00:14:22,440 Hit enter and now you can see, 159 00:14:25,110 --> 00:14:34,580 Set is having only 2 users left. So that's how you deal with Sets and you perform operations on Sets . 160 00:14:34,580 --> 00:14:40,250 And again remember whatever we are doing through commands, basically you are, you going to use a programming 161 00:14:40,250 --> 00:14:43,490 language in real world, to interact with Redis. 162 00:14:43,640 --> 00:14:48,560 So either you are going to use Python or Jython or any other programming language. 163 00:14:48,560 --> 00:14:55,700 And basically it is your application, which is going to be interacting with Redis. so all your logics are 164 00:14:55,700 --> 00:15:01,520 going to be defined in programming language and based on that language, you are going to make a choice 165 00:15:01,640 --> 00:15:07,130 on which command you want to use and what is the operations you want to perform. 166 00:15:07,250 --> 00:15:10,130 Again all of these will depend on the Use Case, which you have.