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  • creating these classes requires equipment and service.

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  • Welcome back.

  • So today's video.

  • I'm going to do an introduction to databases in regards to cloud computing.

  • Now I do have to warn you, and you have to warn you, if you are an expert in databases, turn back now turn back.

  • Now leave.

  • Go away!

  • Watch game of Thrones.

  • The way that I'm going to probably do this introduction today is most likely going to piss off a lot of old school database administrators, because the problem that I have is when I am talking to people, I am talking to new people.

  • And so I have to find someplace to start in order to give folks context for everything else that I talk about later.

  • And so one of the issues you run into when you're doing introductory classes is you frustrate a lot of the old timers because they're like that's That's not Howard is a lorry, and you're like, Well, yeah, you know, in the real world, it gets a lot more complex.

  • And, ah, there's a lot of stuff in the real world, but I have to find some place to start from.

  • And so I am going to be started by talking about relational databases.

  • I think this is a good place to start when we start talking about databases, especially in the cloud computing world, because we're like relation.

  • All databases are most likely the types of databases that you will have run into in your normal day to day work and the type of databases that are most likely easiest for you to spend up.

  • S O.

  • There are different types of databases out there.

  • They focus on being able to deal with data in different ways.

  • Basically, relational databases is just one way that's been around for quite a long time now.

  • And if you're going to be dealing with databases such as my sequel databases or Maria de be a lot of the different types of databases out there, basically they're going to be a relational databases.

  • So if you are a database expert, let me be clear.

  • Yeah, I know.

  • I'm glossing over a lot of crap.

  • It's an introductory class, got may cut me a break here, right?

  • So when we start talking about databases, the important thing to be realizing when you're talking about databases is all a database does, or all database software or a service does.

  • Is it stores data in a way that is very easy, basically to search for and to be able to modify.

  • So that's all Oh, a database server does.

  • So this is very important because a lot of times when people start interacting with databases for the first time don't use a piece of software such as access.

  • So access is a piece of data base software that Microsoft creates and the way the Microsoft does everything, which is good from a production standpoint.

  • But it's horrible from an education standpoint.

  • They got a bundle.

  • Everything together s so what you're doing with access databases.

  • Basically, access has the database component, and it has the front and component, and it has the intelligence.

  • Basically, when you deal with access, you're dealing with a full product, right?

  • So one of the problems is when people go out to start using, let's say that's equal or my sequel or Maria D.

  • B, or some of the other database software.

  • They get really confused because they're like, Okay, I installed the database software.

  • Uh, where do I find the front end?

  • Where do I find the intelligence?

  • And it's like, No, no, all the database does.

  • All a database does, is it stores the data.

  • You then have to use some other front end, and you have to code the intelligence or have the intelligence coded for you to make that database actually do something worthwhile.

  • Right?

  • So when you're dealing with a database, most likely again, if you're gonna be using relation all databases, my sequel, mess sequel, something like that, In order to interact with the database, you will be using something called Sequel or structured query language.

  • And basically what that structure query language allows you to dio is it allows you to do things like create databases, create tables, create records, search for database search through databases.

  • Four records within tables.

  • It allows you to modifications a whole bunch of things.

  • But it's very commanding.

  • It's very command.

  • Select X, where block at right.

  • It's kind of like again will be kind of like trying to surf through the world wide Web at the command line.

  • There are tools and other scum called lynx that allows you to actually navigate the World Wide Web from the command line.

  • But nobody other than really hardcore Lennox administrators would actually ever even think about doing something like that.

  • It's just a horrible process, right?

  • And so that's one thing to realize with the databases, get my sequel or whatever Maria de be.

  • Whatever database they're gonna use is is you have the database software.

  • You're able to interact with the database software using something called structure, query language or whatever language that they use.

  • But that's that is horrible and nasty and God awful.

  • And it's not actually how any normal person is going be interacting with the database.

  • How people actually you're going to be interacting with the database is there's gonna be some front end that has been developed.

  • So basically, the front end is either a like a website that you go to or some kind of application has been created for your windows or your iPhone or whatever else.

  • Then there will be intelligent, so basically you have the front end, and then you code you code for that front end to be able to communicate with your data base eso such as, like if you're dealing with something like a WordPress or dribble.

  • Basically, you have a front end of that front end is 80 Mel and CSS and that type of thing you have a my sequel back end, and then you use PHP.

  • So basically, when you insert data So when you create a user account or when you create a post or something like that, basically PHP takes that information and then with PHP, that information is then input it into the database.

  • When you go to read a post off of something like WordPress and you click the link, what happens there is PHP goes, finds the records associated with that post it, then pulls that out of the database depending on the formatting than four mats.

  • It s so that you can then read it.

  • And so then you're reading it.

  • So one of the important things to remember when you're dealing with databases is all the databases does, is it just stores the data.

  • Basically, it stores those records so that you can access them.

  • How you actually access them, though, is generally through some external application.

  • And then there's some programming language that that communicates from that application back to the database.

  • It's kind of think about like a file server, maggot.

  • If you have a file server and you had a whole bunch of documents, you know, Excel, spreadsheets and documents and PDF files or whatever else in that file server.

  • Now imagine.

  • You know the final server, but you don't have word, and you don't have excel or anything that can open up a spreadsheet.

  • You don't have any of that kind of soft right?

  • That's the same kind of thing.

  • Imagine, imagine just a file server.

  • Just the file server.

  • It doesn't have Adobe Acrobat and stole.

  • It doesn't have word or open office or anything installed.

  • All it does is store files.

  • So the files are there.

  • That data is there, but in order to be able to actually access that dad, do anything useful for it.

  • You need an application installed on your computer that is able to read that data type, and then you're able to communicate with it over the network, and then you're able to open it and modify it.

  • Kind of think about that, like with databases.

  • So basically, you have his database software installed on your server.

  • But to really do anything useful with that at a base, you need some kind of external application that's been created.

  • That external application will then be communicating with the database to push poll, do whatever intelligence that data database requires.

  • So that kind of gives you a little bit of a brief idea what we're talking about with the databases just to kind of get you, get you in the right mindset here.

  • So now that you have a brief idea of what a databases, let's go over the white board so I can draw some things out to try to give you a visual representation of what's going on.

  • So I think it'll make a little bit more sense for you.

  • So let's kind of draw this out.

  • Let's do a little bit of a diagram of how this whole database system works and how clients are going to be interacting with it Now.

  • The important thing to be thinking about when I start talking about you know the database is that the modern world of databases has become much more complicated than how it used to be.

  • So I am trying to give you a basis here so that when you start reading and learning more about database is going into the future.

  • You have a base idea of what's supposed to be going on, and then you can understand what functions or features the product that you're looking at offers.

  • So, basically, in the old days, in the old days we had a server.

  • We had the server with the good old CPU fan on it, right?

  • So you have that he have the physical server.

  • You haven't OS installed on the server.

  • And then on top of that OS, you have a database such as my sequel installed.

  • So basically, you're going to have to actually install the saw that the database software.

  • So whether it's my sequel, whether it's Maria de Be, whether it's some type of Oracle product, Mongo D.

  • B.

  • There's a lot of different databases out there.

  • But again, the general that you'll be using is my sequel, and the important thing to understand is you actually have to install that onto the server operating system that you're using.

  • Then, once you have my sequel actually installed on your system within my sequel.

  • The first unit you're going to deal with is a database, right?

  • So the database is the highest unit that you're going to be dealing with within a database server so you can have a database.

  • So, like a lot of times with databases.

  • So if you're having ah WordPress websites So WordPress websites connect back to a my sequel back End.

  • So we talk about a back end.

  • We're normally talking about a database server, so it communicates with a my sequel back end.

  • So for like me, I have ah, Eli, the computer guy dot com.

  • Right?

  • So Eli, the computer guy dot com, uses WordPress.

  • And so for Eli, the computer guy dot com, there is a specific database for the information for Eli, the computer guy dot com on the same server.

  • I have a website called Fail normal dot com, and it has its own database.

  • So the database is kind of like the route right that it's the highest level that we're going to be dealing with when we're dealing with a database server.

  • Then from there, basically, you have software that's been encoded to be a push and pull data to that particular database.

  • So if you go to Eli, the computer guy dot com, right, you go to a website, your computer guy dot com, and you see all kinds of fancy stuff.

  • They're basically what's happening, right?

  • So I have my Web server.

  • My Web server has PHP installed.

  • And so the PHP programming language is communicating with the Eli, the computer guy dot com database, and it basically pushing and pulling a data from that database.

  • So when I sit down and I write a post so I sit down and I write a post and then I click the little published button that then sends all everything that I've written for that post to the database on the database server and then that's written there.

  • Then if somebody wants to read the post, they opened the post up.

  • Basically, the PHP goes to the database on the database server says, Hey, I need the record for this particular post and in that is sent that gets encoded with HTML CSS.

  • And then I am able to view whatever is going on here, so that's kind of gives you the idea of what's happening now.

  • It is important to understand that you can communicate between multiple databases right.

  • So again, since we're going to be interacting with databases basically since appropriate with a programming language, the reality is, is we can connect to multiple databases.

  • So let's say there's one database server here on one database server here.

  • So again, so something like if you're trying to create some application that allows your users to buy products from something like Amadeus amazon dot com.

  • So you have your user, let's say dot com database server.

  • And so you have a user database here, and then you want to connect to amazon dot com for whatever products that they're offering, right?

  • So basically, you want to create an app that connects users and recommends products.

  • Well, since you can code everything out in PHP or Python or whatever programming language, one of things that you can do is you can have your software.

  • Your application you've created.

  • It can communicate with your user database.

  • It can pull out usernames and preferences and shipping addresses and all kinds of stuff, right, and it can also go to amazon dot com's database and pull out products and prices, maybe reviews and other things.

  • And basically it's able to pull all of that information together so that when one of your users goes to a website, they get the recommended recommendations that are most appropriate to them.

  • So it is important, understand, when we talk about these database files, they are the highest level of storage within a database server.

  • But you can communicate with different database files, basically based off of how you encode your software, right?

  • So you're going be sitting there, you're going.

  • Be writing your application of PHP, Python or whatever else, and then you can have that application be able to connect to these multiple different databases.

  • So that's an important thing.

  • Like a lot of people get confused.

  • They try to dump way too much crap into a single database because there's this kind of this idea like, Oh, the database is the largest, like that's the largest unit I can have.

  • So therefore, I'm just going to keep dumping so much crap in that database on.

  • Then you get into a problem where becomes just a mess to try to manage that database because it's containing way too much crab and so is something to be thinking about is no.

  • You can have one database that focuses on one specific thing for your company or your organization, and then you can have another database that focuses on a different thing.

  • And if those two need to communicate, all you do is in a programming language.

  • You write a script that communicates with both both databases and then pulls the information in that it needs.

  • So that's one of the important things to realize when you're dealing with the databases.

  • So then past that.

  • So we're gonna have our server, right?

  • We're gonna have, you know, my sequel, my sequel, Maria de be whatever else installed, and then we're going to have our database.

  • So the data base is the largest again, the largest unit that you're going to be dealing with within a database.

  • Right?

  • So let's say we have Eli, the computer god dot com.

  • You know, this is the database within my sequel.

  • And so we've been here under the database.

  • We're then going to be dealing with something called Tables.

  • So tables are basically containers for the same type of information.

  • So let's say you have a table for user's on and then you have a table again.

  • If we're dealing with something like WordPress, we're dealing with a with a blog's system.

  • Then we have a table for posts, and then we may have another table for pages, right?

  • So basically, once you have that large edited.

  • So the database itself contains all the data for airline computer guy dot com and then within their you have tables and those tables are basically compartmentalized specific information.

  • So you have a user table of post table pages table and again if you go in and you actually look at a wordpress dot com award press database, I think it's like 20 or 30 different tables of different types of information that have to be stored where they store them in different tables to make it easier to be a grew in minister and manage again.

  • That's one of the big things to be thinking about is a realizing professional is trying, trying to compartmentalize content and things into into rational units.

  • So basically somebody can go.

  • Oh, I need to see what the user information is, and I can simply go to the user table within the Eli, the computer guy dot com database.

  • Imagine if everything was just stored in one massive table that could run you into some problems, right?

  • So then once you get past the table, then you have columns in the table, right?

  • So again.

  • So if you're dealing with a user table, you may then have the user I d.

  • So basically, you need one i d.

  • Number.

  • So you need an I.

  • D.

  • Number that is completely unique in a table.

  • Right?

  • So basically, to make sure that no records are absolutely identical again, one of problems you run into in the real world of I t is computers.

  • Computers can't think on their feet, computers can't.

  • Computers can't just invent new ways of doing things right.

  • So if you have two records that are actually absolutely identical, that can run into a big problem for the database.

  • Because imagine if you're doing a search in a table and you're looking for or something, you know, I need the one record that looks like this.

  • What if you have multiple records that are literally identical, right, You can actually run into problems from the computer room.

  • Now, you may sit there and they say, Well, wait a minute.

  • But what if I do a search and I do that search and my results look identical?

  • Well, thing is the first name it maybe be identical.

  • The last name might be identical.

  • The notes may be identical, but the user i d the unique key.

  • It's called a key.

  • The unique key will be different, right?

  • So So, basically, if you're looking at records so let's say use PHP and you're doing a report.

  • So you do PHP and you're doing a report.

  • You say I want this information, this information, this information Well, you may get you know, Bob, Bob, Billy And you know, is aged 12 and you may get Bob.

  • Billy is age 12 and make it Bob.

  • Billy is age 12 and say You say, Well, wait a minute, Eli, These records are identical.

  • When I when I asked for this information, I got three identical Bob Billy, age 12.

  • But what may not be printing out on that report that you're looking at is that there's a customer I d field and so this Baba Billy a 12 maybe record 101 in this Bob Billy A 12 maybe record 1000 and one in this Bob Billy A 12 Maybe record.

  • I'm 55.

  • And so I know, like right now that may not seem you may be like, Well, I don't understand why that matters, but the important thing is is when you're doing searches, when you're trying to modify records, when you're doing that type of thing, you need some kind of unique idea for the records that you're dealing with or things are going to get really, really bad.

  • They're really, really fast, right?

  • And so when you're dealing with the table, the first thing that you'll have in your table is some kind of unique key.

  • It's called a key.

  • You need a unique key within the table so<