1 00:00:02,160 --> 00:00:03,860 Now to come to an end, 2 00:00:03,930 --> 00:00:07,520 I now also want to add a little database to this whole thing 3 00:00:07,560 --> 00:00:12,900 so that we don't store the data just in our in-memory storage which will be lost whenever we restart 4 00:00:12,930 --> 00:00:18,930 the server or when we're running out of memory and our server needs to free up some memory, instead 5 00:00:18,930 --> 00:00:25,440 I now want to use a real database and of course you can spend hours or a complete course on just databases 6 00:00:25,620 --> 00:00:30,090 and indeed I have a complete guide on MongoDB which is a database 7 00:00:30,240 --> 00:00:34,680 in case you're interested in that as well besides my Node.js course. So definitely check out these two 8 00:00:34,680 --> 00:00:40,530 courses if you want to learn more about Node.js or MongoDB which is a very popular database engine 9 00:00:40,830 --> 00:00:44,540 that works together with Node.js as particularly well 10 00:00:44,880 --> 00:00:48,220 and indeed it's this MongoDB thing which we will try out now. 11 00:00:48,300 --> 00:00:53,970 You can visit mongodb.com to learn more about it and get started and what we will use here is 12 00:00:53,970 --> 00:01:00,360 a cloud service they offer so that we don't have to install and administer a local database which is 13 00:01:00,360 --> 00:01:04,720 a lot of work. For that you should sign in here or try free to create an account, 14 00:01:04,830 --> 00:01:06,020 it doesn't cost you anything, 15 00:01:06,030 --> 00:01:07,930 you just need to create an account here 16 00:01:08,040 --> 00:01:13,770 and once you did create such an account and you did sign in, you will either end up on a screen like this 17 00:01:13,860 --> 00:01:17,490 or on a welcome screen where you can build your own new cluster. 18 00:01:17,490 --> 00:01:24,240 You can simply walk through all that cluster configuration then and pick the AWS option here, pick 19 00:01:24,240 --> 00:01:28,920 something where you see free tier available so that it doesn't cost you anything to get started, 20 00:01:28,980 --> 00:01:34,400 leave all the other default settings here but double check down there for the cluster here that you're 21 00:01:34,410 --> 00:01:38,530 going with one which is free tier eligible, 22 00:01:38,670 --> 00:01:44,100 that would be this M0 sandbox which I can't choose here because I already created a cluster based on that, 23 00:01:44,100 --> 00:01:47,540 you should be able to choose that and then leave all the other settings, 24 00:01:47,640 --> 00:01:50,150 give it any name you want and create that cluster. 25 00:01:50,140 --> 00:01:51,630 Now I already did that here, 26 00:01:51,630 --> 00:01:56,090 I do have such a cluster here and this is just a cluster for multiple databases 27 00:01:56,130 --> 00:02:02,710 you can add. Now click on connect thereafter to learn how you can connect and there on connect your application 28 00:02:02,710 --> 00:02:06,370 and there, this URL will become important later. 29 00:02:06,400 --> 00:02:14,290 Now actually before we do that however, go to database access and there you can create a new user with 30 00:02:14,290 --> 00:02:21,390 any password of your choice which needs to have at least read and write access to your database. Also 31 00:02:21,420 --> 00:02:25,450 go to network access and there under IP whitelist, 32 00:02:25,510 --> 00:02:30,670 click on add IP address and make sure you add your local IP address, you should see this option here 33 00:02:30,790 --> 00:02:33,090 if you haven't added it already as I did, 34 00:02:33,130 --> 00:02:37,780 so your local IP address should be added here. With that you can go back to clusters 35 00:02:37,900 --> 00:02:44,710 and now we can connect our application to this. The question of course is, how do we now use this URL 36 00:02:44,760 --> 00:02:51,520 here? How do we now connect to this database? And for that you can search for Node.js MongoDB driver 37 00:02:51,910 --> 00:02:56,950 and you should find this page here, where you can learn more about the MongoDB driver which 38 00:02:56,950 --> 00:03:02,440 is simply a third-party package for Node.js that makes working with MongoDB and sending requests 39 00:03:02,470 --> 00:03:08,670 to it very easy. You just need to run this command here, npm install mongodb --save, 40 00:03:08,860 --> 00:03:14,890 so let's do that in our Node.js application, not on the frontend, you won't communicate directly to 41 00:03:14,890 --> 00:03:15,910 the database from there, 42 00:03:15,970 --> 00:03:17,970 we do that from our backend 43 00:03:18,040 --> 00:03:21,490 and with that done, we can start using that driver. 44 00:03:21,540 --> 00:03:26,590 Now of course you can learn all about the driver here in the documentation here, by clicking on reference 45 00:03:26,590 --> 00:03:31,410 here for example, you can learn more about installing the driver and how to use it 46 00:03:31,540 --> 00:03:37,270 and we're interested in the CRUD operations, which stands for Create Read Update and Delete because we 47 00:03:37,270 --> 00:03:40,120 want to add data, we want to read data, 48 00:03:40,120 --> 00:03:41,940 these are two things we want to do here. 49 00:03:41,950 --> 00:03:45,950 Again if you want to learn more about MongoDB and Node.js and how they work together, 50 00:03:45,970 --> 00:03:52,750 my Node.js course and my MongoDB course are great to dive in because in both I cover MongoDB 51 00:03:52,750 --> 00:03:54,340 and in both 52 00:03:54,340 --> 00:04:00,240 I also cover a bit of Node.js of course with the different focuses depending on the course title. 53 00:04:00,250 --> 00:04:02,740 Now here you see quite good examples though, 54 00:04:02,770 --> 00:04:08,260 for example for how you add something to the database and therefore we'll build up on that. 55 00:04:08,350 --> 00:04:14,650 It all starts by importing this Mongo client, so let's copy that code, go to our location.js file in 56 00:04:14,650 --> 00:04:23,340 the routers folder and import this here and then we want to perform in such an insert operation when we 57 00:04:23,340 --> 00:04:24,940 get a new location. 58 00:04:24,960 --> 00:04:32,900 Now we need our connection URL, so we can copy that and set this up globally here in location.js 59 00:04:32,900 --> 00:04:36,050 as well outside of our middleware functions 60 00:04:36,160 --> 00:04:42,520 and this URL here of course should be the URL you find on your cluster, so you can just copy 61 00:04:42,520 --> 00:04:49,470 that URL and enter this here and now replace user name with the name of the user you created and 62 00:04:49,480 --> 00:04:51,100 the password as well, 63 00:04:51,100 --> 00:04:59,180 so in my case I'm working with Maximilian as a user here and I am using a password which by the time 64 00:04:59,180 --> 00:05:04,720 you're watching this of course will have been changed already. Now in this connection string here, this 65 00:05:04,780 --> 00:05:09,570 /test thing, that's the database you want to connect to and you can specify any name you want here, 66 00:05:09,610 --> 00:05:14,670 if it doesn't exist yet it will be created on the fly and I'll name it locations and you'll leave to 67 00:05:14,670 --> 00:05:20,870 the rest as it is. Now back to this CRUD operations description here, 68 00:05:21,060 --> 00:05:27,450 now we need to create a Mongo client here based on this Mongo client we're importing and we can just 69 00:05:27,450 --> 00:05:34,490 call client like this and pass in this connection URL and then we need to call client connect, 70 00:05:34,750 --> 00:05:39,740 use this callback function which we pass to it and inside of that callback function where we get access 71 00:05:39,740 --> 00:05:46,640 to the connected client, we can then use that client to run queries against it. So we can copy this here, 72 00:05:47,360 --> 00:05:57,440 this entire code and move that into our post route here, using this client here with that callback 73 00:05:57,440 --> 00:05:59,720 function, remove these assert statements, 74 00:05:59,720 --> 00:06:01,080 we don't need to do that here, 75 00:06:01,100 --> 00:06:03,300 you can remove the console logs here, 76 00:06:03,390 --> 00:06:09,780 we should leave that line here where we get access to the database which we connected to on this client 77 00:06:10,380 --> 00:06:15,450 and then MongoDB works with so-called collections and documents. 78 00:06:15,450 --> 00:06:21,660 You have a collection which is like a table of records and you have a document which is like a simple 79 00:06:21,720 --> 00:06:23,790 row in that table. 80 00:06:23,850 --> 00:06:30,330 So we have a collection here which I'll name user locations, user-locations and with insert one. 81 00:06:30,330 --> 00:06:32,750 you can insert one new document there, 82 00:06:32,830 --> 00:06:39,630 the document I want to insert here should have the same format as what I inserted here in my local memory 83 00:06:39,630 --> 00:06:40,380 storage. 84 00:06:40,410 --> 00:06:44,980 We can comment out this code now but I copied the object structure first, 85 00:06:45,000 --> 00:06:49,260 the one thing that differs is the ID. You don't need to add an ID field anymore, 86 00:06:49,290 --> 00:06:52,980 MongoDB will create an ID for you automatically. 87 00:06:52,980 --> 00:06:55,310 Now insert one does not just take this argument, 88 00:06:55,320 --> 00:07:00,090 it also takes a function which will fire as soon as it is done with this operation, 89 00:07:00,090 --> 00:07:07,140 this gives you either an error or the result of that operation and here we can get rid of this 90 00:07:07,140 --> 00:07:10,440 other dummy code with insert many, we don't do that here. 91 00:07:10,620 --> 00:07:11,610 So we're good like that, 92 00:07:11,610 --> 00:07:16,650 we now just want to make sure that here in this function which fires once we're done inserting this, 93 00:07:17,040 --> 00:07:18,680 we send back our response. 94 00:07:18,690 --> 00:07:24,870 So we grab this response code and only send this once this function executes again for all these asynchronous 95 00:07:24,870 --> 00:07:28,520 code logic where this will run at a later point of time 96 00:07:28,530 --> 00:07:31,040 basically once this operation completed. 97 00:07:31,170 --> 00:07:35,520 Now theoretically, we should also check for errors here and send back a different response if we got 98 00:07:35,520 --> 00:07:36,150 one 99 00:07:36,150 --> 00:07:41,280 but to save some time here and not make this overly complicated, for now we'll just assume that this 100 00:07:41,280 --> 00:07:42,120 always works, 101 00:07:42,180 --> 00:07:47,420 again more detailed error handling and so on is covered in the dedicated courses. 102 00:07:47,520 --> 00:07:49,620 So now here we're storing this, 103 00:07:49,620 --> 00:07:54,060 the ID I want to send back has to be retrieved from that result we get here 104 00:07:54,060 --> 00:07:54,630 however. 105 00:07:54,840 --> 00:08:02,550 So for that let's console log r so that we see what's in there when we store something and with that, 106 00:08:02,870 --> 00:08:07,220 let's restart our node application here and let's give this a try. 107 00:08:08,140 --> 00:08:12,370 When we find a place here, that's generally looking good 108 00:08:12,370 --> 00:08:14,240 okay now we got an error here, 109 00:08:14,270 --> 00:08:20,860 now let's see what went wrong here on the backend by expanding this log and we cannot read DB of 110 00:08:20,860 --> 00:08:23,140 null is the problem here, 111 00:08:23,170 --> 00:08:25,720 yes because DB name here of course does not exist, 112 00:08:25,720 --> 00:08:32,800 I don't have such a variable. My DB name is locations, so we should just enter locations here, 113 00:08:32,800 --> 00:08:37,570 I remove that DB name constant from the example or didn't add it to be precise. 114 00:08:37,570 --> 00:08:42,940 So we want to connect to the locations database or use the locations database to which we connect here 115 00:08:43,730 --> 00:08:49,370 and now with that changed, let's restart this backend server and 116 00:08:49,370 --> 00:08:55,560 let's give this another try by again finding a new place here and now this didn't throw a new error, 117 00:08:55,590 --> 00:08:56,690 if I cleared the errors, 118 00:08:56,700 --> 00:09:01,980 we don't see a new error here and indeed here we get a success response and this is the object we get 119 00:09:01,980 --> 00:09:08,550 back by MongoDB, quite a complex object. In the end what it will have though is an inserted ID property 120 00:09:08,550 --> 00:09:10,480 which is just what we need here. 121 00:09:10,500 --> 00:09:19,040 So we send back here not ID but r.insertedId, that's what I want to send back to the client 122 00:09:19,810 --> 00:09:24,020 and now we don't need to generate our own ID here anymore. With that 123 00:09:24,030 --> 00:09:28,200 if we now restart this and we find a new place, 124 00:09:29,340 --> 00:09:33,980 now you see here we got this ID which is generated on the backend. 125 00:09:34,230 --> 00:09:41,310 So with that we're storing data in MongoDB, now retrieving it would also be nice when we send the get request 126 00:09:41,940 --> 00:09:46,550 from this page because right now of course we fail here because we have no logic to retrieve our data 127 00:09:47,070 --> 00:09:50,390 but the MongoDB driver docs got us covered. Here 128 00:09:50,400 --> 00:09:58,140 if we scroll down, we find more functions we can execute, for example for updating and for deleting documents 129 00:09:58,160 --> 00:10:02,190 but I want to find a document, 130 00:10:02,190 --> 00:10:05,880 so we want to have a look at the read methods here and there, 131 00:10:05,880 --> 00:10:12,510 again we have all the logic for connecting. In the end, what we can do here is we can just copy this code 132 00:10:12,510 --> 00:10:20,220 here from our add-location route into this get route here 133 00:10:20,400 --> 00:10:26,310 after we retrieved the location ID, effectively replacing this code where we use the memory database 134 00:10:27,120 --> 00:10:33,390 and I still want to connect to my client here, reach out to the database and reach out to the user 135 00:10:33,390 --> 00:10:39,360 locations collection but now of course I don't want to insert one, I want to find one document instead 136 00:10:39,360 --> 00:10:46,230 and you still pass an object to find one but here, you specify the criteria for finding a document and 137 00:10:46,230 --> 00:10:48,730 you can find a document by ID here. 138 00:10:48,990 --> 00:10:55,530 The ID is actually stored on an _id field in MongoDB, so we can use _id here 139 00:10:56,040 --> 00:11:01,340 and then use the extracted location ID which no longer should be a number, 140 00:11:01,350 --> 00:11:04,490 so let's remove the plus here as a value. 141 00:11:04,530 --> 00:11:10,890 So now we will try to find a document where the ID is equal to that location ID as a string which 142 00:11:10,890 --> 00:11:13,630 we retrieved from the URL. 143 00:11:13,740 --> 00:11:18,630 Now we have to pass a second argument to find one which is this function which executes once this operation 144 00:11:18,630 --> 00:11:19,380 is done, 145 00:11:19,470 --> 00:11:24,070 we either get an error or we get the document which we are looking for 146 00:11:24,180 --> 00:11:26,570 and here I expect to get the document, 147 00:11:26,610 --> 00:11:32,580 so when we return something here, I of course want to use this logic from before. 148 00:11:32,640 --> 00:11:39,540 I'll cut that code and add it here and check if we don't have a document for some reason, in which case 149 00:11:39,540 --> 00:11:46,480 I still return the not found error but if we did find one, then I wouldn't return a response where the 150 00:11:46,480 --> 00:11:50,130 address can be found on the document, 151 00:11:50,230 --> 00:11:58,860 there it is stored such that we have an address property and also get the coords from the document and 152 00:11:58,860 --> 00:12:03,400 the rest should be able to stay as it is. So let's give it a try, 153 00:12:03,430 --> 00:12:12,610 let's save that and rerun the server here and now let's reload this place. Now I still get could not 154 00:12:12,610 --> 00:12:18,540 find location and the reason for data is something MongoDB specific, 155 00:12:18,540 --> 00:12:24,790 the ID of an element which is added to the database is not actually a string, 156 00:12:24,870 --> 00:12:30,660 it's a special data type MongoDB uses internally, it's an object ID which is not a Javascript 157 00:12:30,660 --> 00:12:35,970 data type but a MongoDB specific one. Now when you query for an ID here, you therefore have 158 00:12:35,970 --> 00:12:44,640 to look for a such an object ID data type. You can do so by using that Mongo client, thankfully it's 159 00:12:44,640 --> 00:12:51,070 not too hard to do that however. When we import our MongoDB package here, we can not just reach out 160 00:12:51,070 --> 00:12:52,440 to the Mongo client here, 161 00:12:52,860 --> 00:13:01,730 let's restructure this a bit and import MongoDB here just from MongoDB and get the client then from 162 00:13:02,360 --> 00:13:08,270 MongoDB.client so that we can get other things out of MongoDB as well because the other things 163 00:13:08,270 --> 00:13:15,710 I'm interested in in this case here is this object ID constructor. We can use MongoDB object ID 164 00:13:15,710 --> 00:13:21,260 here and call new in front of it because this actually is basically a class which you can construct 165 00:13:21,740 --> 00:13:24,580 and to that, you pass your ID as a string, 166 00:13:24,620 --> 00:13:30,620 so in our case location ID and it will wrap this in its own data structure which now can be used in 167 00:13:30,620 --> 00:13:35,230 a query and with that change made, we restart that server, 168 00:13:36,790 --> 00:13:42,500 we can go back here, reload this place and we get this place here and that's it. 169 00:13:42,520 --> 00:13:44,950 Now this is by no means a finished server, 170 00:13:44,980 --> 00:13:54,010 we could do far more on this server, improve error handling, add more scenarios, make this code more reusable 171 00:13:54,040 --> 00:13:59,700 and not always create a new connection here but this is just there to get you started with Node.js 172 00:13:59,700 --> 00:14:04,300 and even MongoDB which is not directly related to Javascript after all 173 00:14:04,300 --> 00:14:09,010 and it's there to show you how Javascript is able to run in different environments and how you generally 174 00:14:09,010 --> 00:14:16,200 have the same syntax but still can do very different things with it and that's therefore it for this module. 175 00:14:16,390 --> 00:14:22,180 As I mentioned multiple times, if you want to learn more about Node.js and/or MongoDB, I got dedicated 176 00:14:22,180 --> 00:14:28,000 courses for that, in my Node.js course for example, I also spend a lot of time on MongoDB diving way 177 00:14:28,000 --> 00:14:33,940 deeper into it and showing you how you can connect it to Node.js in various different ways and therefore 178 00:14:33,940 --> 00:14:37,190 these are the resources you want to dive in if you want to learn more, 179 00:14:37,210 --> 00:14:42,760 this hopefully still gives you a great overview of what you can generally do there and how that works.