Node.js Crash Course Tutorial #9 - MongoDB

a rather than gang so now we've figured out how to use templates and middleware I want to go one step further and introduce a database to the mix as well so we can store data in that and then we can get that data and inject into our views when we need to so when we're working with databases there's a couple of main types we typically choose from the first type is a sequel database like my sequel and the second type is a no sequel database and both of those structure data differently so sequel databases use tables rows and columns to store records of data and no sequel databases instead make use of collections and documents now the one that we'll be using is called MongoDB and that is a no sequel database so how exactly does a no sequel database work well it split up into collections and they are a bit like tables in sequel databases so each collection would be used to store a particular type of data for example a user collection would store user documents now in our case for our project we might have a blog collection to store up blog documents and you can have as many different collections as you want but the important thing to remember is that each one would contain only one type of document be it user blog author or something else so each collection would store documents and in our case that is going to be blog documents now a document is a bit like a record in a sequel database each one represents a single item of data so a blog document represents a single blog now these documents are stored in a format that looks very similar to JSON or JavaScript objects they basically hold a series of key and value pairs for example a blog document could have a title a snippet and a body property and it would also have this auto-generated unique ID to identify it as well so from our code we could connect to a collection like the blocks in MongoDB and then we could either save read update or delete documents inside it so let's start by creating a database and hooking it up with our code southern when we're working with MongoDB there's a couple of different setup options that we can use we can either install MongoDB on our computer locally and use and then deploy that or we could use a cloud database which is already hosted for us and it can be quite a lot easier for us to manage so we're gonna do that now the cloud service we're going to be using to make this database is called MongoDB Atlas and you can find that at this web address which I will leave down below now it's completely free to begin with and you can sign up for a free account right here by clicking on this button and just signing up I already have an account so I'm gonna just log in right here with my Google account and then when you sign up you should see this page now it might look a little bit different when you view this depending on when you're watching the video they do change their design a little bit but the functionality underneath is the same so the first thing we need to do is to build a new cluster so click on that button and we want to create a free one unless you've got money to splash and you want to sign up for one of the premium options then we want to choose a provider and the region I'm going to stick with the defaults right there we can give our cluster a name if you want I'm just going to call this notes like so you can leave it as the default if you prefer it really doesn't matter at the minute especially for this tutorial and then it's going to just take a couple of minutes to create that cluster so then once that's done the next step is to create a database and a collection inside that database so let's click on collections to do that and then we want to add our own data we need to give this database a name call it what you will I'm gonna call it node toots and then we need a collection name remember a collection is where we're going to store a load of documents of a certain type so we're gonna stop blog documents for our blog in there so we'll call this blogs makes sense and I'm going to create this collection so this is our collection right here there's no documents in it at the minute what I'm gonna do now is create a user so that we can use that use it for database access from our code over here so let's go to database access and create a new database user I'm going to call this net ninja and the password is gonna be test one two three four please create something that's more unique than that and more secure we need to give read and write access to any database and I'm gonna add user or right here so I'm going to use that use it later on the username and the password I created from our code so that we can connect to the database that way not anyone can just connect to the database only invalid user that we declare or write here so some kind of admin user all right so now we need to go back to clusters and we need to figure out a way to connect to this database so I'm gonna connect right here and then we want to connect from our application like so and this connection string we're going to need later on so I'm gonna copy this right here and I'm gonna go back over to our app file and I'm going to create for now just a new variable so Const and I'll call this DB URI and set it equal to this string like so so we're going to use that shortly to connect to our database and in fact I'm gonna grab that and I'm gonna paste it actually below where we declare our app and I'm going to also do a little comment that says connect to MongoDB so this is the connection string that we're going to use later on to connect to our database and we're going to replace this right here with our username which is net ninja which we just created right and this is test one two three four that was our password so then now we need to actually connect to the database and we could connect using the plain MongoDB API and package and we could use the regular MongoDB API to make queries to the database too but that can sometimes be a bit clunky and verbose so instead we'll be using something called Mongoose to connect and interact with the database which I think makes it a bit easier and it's nicer to work with so let's take a quick look at what Mongoose actually is okay they're my friends so Mongoose is an odm library and that is an object document mapping library and that basically means that it wraps the standard MongoDB API and it provides us with a much easier way to connect to and communicate with the database now it does this by allowing us to create simple data models which have database query methods to creates get deletes and update data based documents now under the hood mongoose does all the heavy lifting for us it queries the correct database collection for us based on the name of the model we use and then it performs the action required and returns us a response now you don't have to use Mongoose you can just use the standalone MongoDB library if you prefer but sometimes it can feel a bit more clunky and verbose so we're gonna use Mongoose and let me break down exactly how we're going to be using it in our project so the way we generally work with MongoDB and Mongoose is to create schemas and models now this is quite similar to how we typically work with any kind of data resource we'd make a model to represent that data resource now in Mongoose though we make a schema first now the schema defines the structure of a data type or document stored in a database collection it describes what properties it should have the type of those properties etc so for example a user data type might have a user name bio and an age now in our case we're working with blogs so we'd have a schema for a blog now that's going to have three properties it's going to have a title snippet and a body and it's also going to have an auto-generated ID property as well now these properties are all going to be of type string and all of the fields will be also required so our schema will define the structure of our blog documents or like this and that will be the structure of documents stored in our blog collection in a database now the next thing we do is to create a model based on that schema now the model is the thing that actually allows us to community with a particular database collection for example if we create a block model which is based on a blog schema the blog model will then have both static and instance methods which we can use to save update delete or read data from the blog's collection so that's kind of the theory behind it don't worry so much if you don't fully understand it yet we're gonna have plenty of practice and let's start by using Mongoose to connect to the database okay then so the next step is to actually connect to the database using Mongoose so to do that we have to install Mongoose because it is a third party package and we'll say NPM install Mongoose to do that so we can then require it up here by saying Const Mongoose is equal to a require and the package name is Mongoose so now we can use this Mongoose object right here to connect to the database and I'll do that down here by saying Mongoose and then use a method called connect like so now this expects as an argument a connection string like this now before we pass it in I do want to make a quick change to this at the minute it's going to connect to a test database that's what this means right here but we want to connect to this database node touch that we create it so I'm going to replace test with whatever this says right here so node totes so that it connects to that database like so okay so now I'm going to pass this thing right here this constants into this connect method and then Mongoose is going to go out and connect to that database forest now if I was to save this right now and run it we might get a deprecation warning so let me say node on app to run this and you can see right here we get a deprecation warning now you can leave that if you want to it's not really going to affect how we use the code but what I'm going to do is pass in a second argument which is an options object to this connect method so I'm just gonna paste this in you can pause it and write it as well and this is just going to stop those deprecation warnings but like I say it's not going to affect how we write the code in the future so now if I save this and run file again we shouldn't get those deprecation warnings down here awesome now this right here is actually an asynchronous task it goes out and it takes some time to do and therefore it returns something like a promise and we can tack on the then method to it so this then method takes in a callback function which is gonna fire when this connection is complete after it's connected to the database and we get a result in this callback function which we can use if we want to I'm just going to say in here console dot log connected to DB and we also get a catch method in case there's an error we can catch the error and we'll do that inside a callback function and we'll log that to the console as well now hopefully there won't be any errors but let's just test this out we should hopefully see this logged it to the console or right here so let me save this and run it and you can see it takes a little bit of time but after a couple of seconds we should see this thing right here connected to the database awesome so that works now that if you think about it we don't really want our server to be listening for requests until this connection has been made because for example if a user requests the home page and that home page lists a load of data dependent on the database then we can't show that until the connection to the database has been established so we really don't want to be listening for requests until this is completed so what we could do is we could take this and we could paste it inside this then block instead and then we're only going to listen for requests after this connection is complete and that makes sense so let's delete this down here save it and make sure there's no errors which that's not awesome okay so the next thing to do now is to create a schema and a model for our blog data so I'm going to create a new folder for all of my models and schemas over here and I'm going to call that folder models now we want to create a model and a schema for a block so let's create a new file called blog jas alright so inside here the first thing we need to do is require mongoose so const mongoose is equal to holy choir and it's going to be the Mongoose package then we also need to get something from the mongoose object right here and that is the schema so I'm gonna say Const scheme up with a capital S is equal to Mongoose dots scheme out with capital S okay so remember a schema is the thing that is going to define the structure of the documents that we're gonna later store inside a collection it's the thing that a model wraps around okay so this thing right here is actually a constructor function and we're going to use it to create a new schema and we're going to store that in a constant now you can call your schema whatever you want I'm going to call it blog schema that makes absolute sense to me and that is equal to a new schema so this creates a new instance of a schema object now we need to pass in an object as a parameter so that this object can describe the structure of the documents that we want to store in our blocks collection ultimately so right here we can add the different properties that we want our blog objects to have for example I want to have a title right I want that to be a property of our blog documents now right here I can also say that this has to be a string type now I also want to say this is required so instead of just doing that I'm going to open this up into an object and therefore we can add some extra validation as well so we can say the type is going to be a string but also we're going to say that required is true and that means that this field is required for blog documents alright so then let's do some more fields we also want our blogs to have a snippet property and again let's open up an object so we can add the type which is also going to be of type string and it's also going to be required right so this is Mongoose creating a schema for us and we're allowed to say what type of dates each property be and whether it's required or not so let's just add one more which is the body and this also is going to be of type string and we also want to make this required like so alright then so they're the only three properties we really want on our blog schema now after this object right here we can pass in a second argument to this schema constructor and this is a bit like an options object now what I want to do is set time stamps in here to true and this automatically generates time stamp properties for us on our blog documents as well so like a created and updated a property and every time we therefore in the future update or create a blog document it's going to auto assign values to those properties for us and we'll see that later on when we see the data inside our collection okay so first thing you need to do is spell time stamps correctly so time stamps like so now the next thing we need to do is create a model and that model is going to be based on this blog schema so remember the schema is the thing that defines the structure of our documents the model is the thing that surrounds that and then provides us with an interface by which to communicate with a database collection for that document type so I'm going to create a new constant down here to store this model in and typically the names of these models are given a capital letter so I'm going to call it blog with a capital B and I'm going to set that equal to Mongoose and then use a method called model now this model takes in as a first argument the name of this model now the name of this is important I'm going to call it blog the reason it's important is because it's going to look at this name it's going to pluralize it and then look for that collection inside the database whenever we use this model in the future to communicate with the database so it's gonna therefore look for blocks right because we've called model blog so when it connects is going to look for this blocks collection right here automatically so we don't need to ever say in the future look I want you to search the blog's collection whenever we use this blog thing right here in the future to find something because we're going to get access to different methods on this in the future provided by the model then we don't need to say find the blog's collection it's going to automatically look for the blog's collection based on this name alright so that's the first argument we passed in the second argument is going to be the schema we want to base this model on so what type of objects and we're going to store inside this collection well it's going to be the blog schema and we just created all right so that's it two steps we make our schema which defines the structure and then we create a model based on that schema and we define the name of this model which should be the singular of the collection name and we store that inside a constants or right here finally the only thing we have to do now is export this model so we can use elsewhere in the project so remember to do that we can say module done exports and set that equal to the blog view there we go there my friends we have created our blog schema and our blog model and now we have this model we can use it to save some new blog documents to our database collection okay then so now we have our blog model right here let's try using this in the code to interact with the database so that inside app J guess what I'm gonna do is create just a handful of sandbox routes if you like just to test out this interaction with the database so what I'm going to do first of all is a get handler app get which is going to respond to requests to /add - block and this is going to be used to add a blog to the collection so we'll fire a callback when that request comes in taking the request object and the response object and inside what we want to do now is create a new instance of a blog documents and then save that to the blog's collection in the database so first of all we need to import the model that we exported right here so let's do that right at the top so I'm going to say Const blog is equal to require and we want to go into the models folder so dot forward slash models and then we want the blog file okay cool so we have that now we can create a new instance of a blog by saying down here Const blog and you can call the constant wherever you want this is just what I am calling it and then set that equal to a new blog so we're using the model to create a new instance of a blog document within the code and in here we pass an object with the different properties of this blog now remember inside our schema we said that each blog should have a title which is a string a snippet which is a string and also a body which is a string we don't have to pass this in Mongoose automatically takes care of the timestamps for us so just these three things right here that we need to worry about so let's add in a title property and that is going to be new blog very rich all right and the snippet is going to be about oops about my new blog all right and then the body is gonna be more about my new block I really pity the people to go and read my blog because this is about as interesting as it's gonna get anyway we have that new instance of the blog now and we can use a method on this to save it to the database and it's dead simple to do that we just say blog which is the new instance we just created using the blog model and then we use a method on it called save so when we get a new instance of the blog model it gives us a load of different methods that we can use and we're using one called save to save this to the database now under the hood mongoose is going to say well okay we've used the blog model therefore i'm going to look for the blog's collection based on this name and i'm going to take this document that you've created with this information and i'm going to save it to the blog's collection and it goes out and it does that for us now this is an asynchronous task it takes some time to do it goes off and does it it might take a second to do probably less but nonetheless it takes some time and it returns us a promise so we can tack on a then method which is going to fire a callback function when this promise resolves ok so inside this callback function we get the result and what we're gonna do is just send back a response so response does send and we're going to send back the results so we can see that in the browser and we also want to attach a catch method to this just in case there was any kind of error with this action and we're going to log that to the console if there is one console don't log error ok so dead simple right now let's try going to this URL in the browser so let me say a local host 3000 /ad - blog and we get this response in a browser and this looks like a javascript object right we have the curly braces and curly braces there and we get an ID this is auto-generated for us we're gonna title which is the title we give it the snippet about my new blog body etc we also get these time stamps that Mongoose created for us right here as well so this thing right here this object kind of thing that we're seeing is actually the new document object that is being sent back to us in the code once this action is complete so once mangu saves it to the database the database then sends us back an object version of that new document so not this object right here this is slightly different because it doesn't have those timestamps or the ID on it or anything like that it sends us back the actual documents inside the collection that it's saved right and if we actually go to the collection now over here what I'm gonna do is just refresh by clicking this button and we should see that that document is inside this collection now we don't because I just noticed I made a spelling error over here but it's actually connected to the node tooks database which is what I specified in my string right here so that database didn't exist it's going to created that for me because I was a bit of a plonker before and created one called notes totes but anyway it's created this database for me but it also demonstrates a point if this collection didn't already exist then it creates it for us which is nice so in there we can now see that we have total documents one right here and this is that new document right you can see all of different properties match up and that is what is being sent back to us here in the browser because we send it all right here okay sweet so that is how we add a new block if I wanted to add another one let me say new blog to save it if I go to this URL again add a blog then it's gonna add another one and we should see a new blog too over here now that's the new document it's sending back and if we go to the database and a refresh over here we should see two documents inside here now we can see new blog and new blog too awesome so that's how simple it is to save documents to the database all right so let's do another one to actually get all the blocks so say we want to retrieve all the blogs from the collection well I'm gonna do another handler and this is for /all blocks and will fire a callback function which takes the request object and also the response object and inside that function we need to then use the block model to get all of the documents from this collection now this time we don't need to create a new instance of a block because we're not creating a new document we can just use a method directly on this blog model so down here I'm going to say block with a capital B and then I'm going to use the method find and that gets us all of the documents inside the blog's collection it goes out and gets all of them now again it's asynchronous it takes a little while to do so we can tack on a then method to it which fires a callback function with the results from the database when it's finished now all I'm going to do is send that response to the browser so I'll send the result which should be a list of documents right this time and we also want to catch any errors so let's do that as well and console dot log the error okay so then let's try this I'm going to go to forward slash all blocks over here so all - blogs and we should get to with them yes we do inside what looks like an array so we get two objects very simple right so that's all there is to it we use the model and we use a method on that model called find so when we save it we use an instance method right here on the instance of the blog that we create when we're finding them we use a method directly on the blog not on an instance of the block so there is a difference right there okay so let's do one more let's try and find a single blog so let's do another handler app gets and this is going to be for a single blog so forward slash single - blog and we want to fire a callback function when a request comes in for this and inside here again we use the blog model and this time I'm gonna say find by ID okay so you know when we saved a new document to the database look at this idea right here this is an object ID right here now this is a unique type and it's not a string when it's stored in MongoDB but when we're using Mongoose it handles the conversion of this into a string and back again when we need it so if we want to find something by an ID we can just pass in a string here and then Mongoose is going to handle that conversion into an object ID to compare it to one of these documents and retrieve that single document so if I go to all blogs I could just get this one right here for example which is the first one new blog and if I paste that right in here like so it's gonna go out and it's going to find the blog with that ID so again it's asynchronous we can check out of their method which will fire a callback function when this is done and inside that function I want to take the result back from the database and that should be a single document this time and I want to send it as a response to the browser so response don't send the results again I'm just gonna copy and paste this catch block right here we're gonna catch any error if there is one and log it to the console so let's try this I'm gonna get a single blog so let's just delete all that a single - blog and we get that one blog now if I change this so we use the other ID so if I get this one right here which is blog to see if this works okay save it and go to single blog and refresh we should get new blog - this time which we do awesome so there become a friends that's the basics of how to interact with this database so we've seen how to save a new blog how to find all the blogs and also how to find a single blog based on the ID we're also going to see how to delete blogs later on and we're going to put this kind of logic improper outs later on because this the minute is not the way I want to go I don't want these kind of routes I want to integrate these into my routes that we have down here and maybe create some more in the future so they're my friends now we know how to interact with the MongoDB database using Mongoose now we can delete these kind of sandbox routes that we created and instead apply this kind of logic in some of our routes down here and we're also going to make a couple more as we go forward as well so these are the routes we have at the minute we have a home page right here we also have an about page we have this page as well forward slash blogs forward slash create and that gives us the webform to create a new blog so what I'm going to do is split this up into two so these are our basic routes and I also want to put a comment right here these are the blog routes and I want to create a new one so apt-get and it's going to be forward slash blogs and this is ultimately going to be the route to go to if you want to get a page back where we're going to display all of the blogs now as a matter of fact inside the home page that's what we're currently doing with this dummy data right here but what I'm going to do is do that down here in this handler instead and for the sake of this tutorial instead of rendering of you inside this handler I'm just going to redirect it to this one right here so that if you go to the home page we're forwarded on to the forward slash blogs page and then we render out all of the blocks now if you wanted to instead you could do a separate home page here but like I said for the sake of this tutorial I'm just going to forward it on to this URL so to do that remember we just need to do a redirect and we do that by saying response dot redirect and where we want to redirect to and we want to go to forward slash blogs so now we go to the home page we're redirected to forward slash blogs and that is going to be handled down here in the blog routes just so we can separate these things from the normal routes a little bit okay so we need a callback function we're taking the request object and the response object and inside here the first thing we want to do is get all the blog's now we saw how we could do that we could use the blog model and then use the find method and this goes out and it finds all of the documents inside the blog's collection so attack on the dot then method because this is asynchronous we fire a callback function when this is done now inside this callback function we're taking the result that comes back from the database we also need a catch method to take any error and we'll take that error into the callback function and we'll log that to the console okay so now when we have the result remember when we get all of the blocks that was an array of blocks we want to pass this in to our index view over here if we open this up and go to index remember this expects a property called blocks so what we could do is pass that array of blocks that we get back into that view and we don't need to change any of this code because we're already expecting an array of blocks right here we're cycling through them and we don't need to change any of the code so let's do that let's go down here and render view so response dot render and we want to render the index view and we want to pass in some data now the first piece of data should be the title because we expect that title inside the head over here where we output the title okay so that's the first bit of data we want to pass in so the title in this case is just going to be all blocks okay now the second bit of data we want to pass in is whatever we get back here that's the array of blocks so the property name is going to be blocks and we pass in the results that's all there is to it so then now we're passing in these two things let's save it and go back to the browser so let me come over here and let me go to just forward slash to see that redirect in action we got to fold slash blocks and we're getting all of the documents and now we're outputting those in the view because we're cycling through those we did all of this before with dummy data we're cycling through those blogs and outputting the title and the snippet for each individual blog right so that was pretty nice pretty easy to do now I also want to show you one more quick thing right here and that is the sort method right here so we can sort by a particular field inside our document now I'm going to sort by created at remember these were the time stamps that Mongoose automatically added on for us and I'm going to say minus one right here and that means descending order so it's going to go from the newest to the oldest and the newest now will be at the top of the page instead of the oldest so this should now be at the top of the page so let me save that and we can come over here and refresh and we should see now that blog - it should be at the top of the page once this refreshes yes we do so we are going to be using Mongoose with MongoDB for the rest of this series so we'll also see how to do many more things with it but for now we'll leave it there

Channel: The Net Ninja

Views: 171,667

Keywords: node.js, node, node js, node.js tutorial, node tutorial, node js tutorial, node crash course, node.js crash couse, node js crash course, crash course, tutorial, install node js, install, node.js introduction, what is node.js, what is node js, what is node, node vs deno, mongodb, mongo db, node.js mongodb, node mongodb, express mongodb

Id: bxsemcrY4gQ

Length: 35min 55sec (2155 seconds)

Published: Wed Jun 24 2020