MySQL Basics and Data Retrieval (First Class)

1. Introduction: This is the introductory video of our M school class in which you will know that what we'll be learning in this class. So we'll basically start with the data retrieval. How can we get the data? And then we'll learn to filter the data. And after that, we can go and figure out to sort the data and to limit the number of the raws. And we can also play around with the conditions, which will be used to get the conditional data. And you'll also see the other things as well. And this is what we're going to learn in the first class of our Mcal course. 2. Basics and Data Retrieval: As we are starting our class now. So before going into the learning zone, I want you to let you know that what we will be learning. So for that, I've created the table of content. So we going to start with the introduction to my school in which we'll be learning about the installing part, importing the database and all that. And then we'll cover all the topics that are listed here. And after these topics, we also have five more topics, so we're going to basically end with creating ESS. Okay. So before going into the content of our table of content, I just want you to know some basics. So we're going to basically start with what is database. So by definition, database is an organized collection of our data so that it can easily be accessed and managed as simple as that. So if I put the database in the simple verse, it's just like the place where you store your data, and they're also the types of database. So we have the two type of the database. The first one is relational. And the second one is non relational. And what is relational database? It is the database that organize the data in the Ras and the columns format, which collectively forms a table, just like the Excel file, and what is non relational database? A non relational database is a database that does not use the tableo schema of Ras and columns. So in simple words, we don't use tables in non relational database. So since we have learned about the basic concept about the database, and what are the type of the database. Now is the time to install MSCe. Okay. So before installing the Micco, the first thing that we need to do, we have to download this. Okay? So how can we download this? I'm going to simply search for M ske download here, and here you will be able to see M school download, so we have to click here. And then what you need to do. So here you'll be able to see option of M school community. So we have to click here. And after here, what we need to do, we have to install M sche community server. So let's click here. All right. So as I'm using the MCS, that is why I'm having this on the operating system. But if you're using the windows, you'll get the windows here. Okay. So since I'm using the MC with the arm tip, that is why I'm going to simply download this one. But before that, if you are using the windows, you're going to go here into the windows Microsoft Windows, and you'll be able to see the option of MSI installers. So you can simply download this and from there, we can install MCL. So now I go back and select our operating system. And now click on this download. All right, so from here, I don't have to log in or sign up. I can simply download this by clicking on this link. Okay. So now you can see this. We are downloading our Mico. So it's going to take some time. Al O M sche is being downloaded. So let's click here. We have to open this. And now we have to install this to the double click. Okay, now let's click on Continue. And we have to click on Continue again. Click on continue. Al. So if you wanted to change install location, you can simply do it from here. So I'm going to go here with the default location, so let's click on install. All right. So here you can see the two options here. The first one is strong password encryption. And the second one is the legacy password encryption. All right. So the first option is basically recommended. So let's click on next. And now we have to add our password here. And you have to remember that the password that you're adding here, you have to add this whenever you want to log in into your Mcle or whenever you want to access your Miccle, okay? All right. So I would start M school server later. So let's just finish this. All right. So now Mischel is being installed. So now what we need to do, we have to put this installer into bin, and we have to start our Miccle server first. So we have to go here into system settings. And now you can see the option of M score here. Okay? We have to click here, and we have to click on Start Mickle Server. As our Muscle server is basically working now. So now we need to test this in terminal. So in the terminal, we're going to test our mice. So for that, we're going to write down macule and we'll use minus u here. So basically stand for the user name. So as we know that the default user name is the root, and now I'm going to write down the P, and now you'll simply hit the er, and then you have to write down your password. All right. So now you can see this, we are inside our M school, and our M school is successfully installed. So now just test out the QE here so that would be show data bases. We're going to use SMI column. I the ter, now you can see this, we have the data bases. So this is how we can install M school. Also sometime we get the issue of the path when we install M school for the first time. So how can we resolve that? So if you're having that issue that whenever you're writing down my school, and you get the error that the command is not found. So for that, what you can do, the first thing that you need to do, you have to look for a file So you basically have to look for this file. Z as HRC. Okay? So if this file is not installed, if you can't see this file, you'd basically have to create this file. So how can you create this file? That is really easy. You're going to simply write down touch, and then you're going to write down Z as HRC. That's it. Okay, I have to add the Z here. So you have to create the file if the file is already not created. But if the file is already created, but still you're getting this issue, then what you can do You can simply open up this file. For that, you're going to write on open, and then you're going to write down the name of the file. Hit the inter. Now you can see this. We are having this text here. Okay. So at the top, you can see this, we are having our M school path here. So if this path is not added, you have to add this path. So how can you add this or how can you get the path of Mike? That is really easy? You're going to simply click on the spot. Search for the user here. And now you can see this folder, so you have to click here. And then you have to go inside the local. Inside the local, you will find M school here since we have installed this. Okay? So we're going to go here inside the M school, and here you can see the Bin. Okay. So now what we need to do to get the path of our M school. You simply do the right click here, and you can see the option of copy Bin as path name. But if you can't see this path here, what you need to do, you have to simply click on the view here, and here you can see this option here of path bar. So you have to enable this from here first. Then after this, you can simply copy the path from here. Copy the path from here, then what you can do. You simply put this here after here. So you would simply push this here. Okay? So you have to write down this text first, and after this you have to write down the path of your M school. Okay, so after doing this, what we need to do, we have to reload the file. So how can we reload the file? That is really easy? You just simply write down source here, and that would basically reload our file on current terminal. And after this, the path of M score will be added, and then we can simply access our M score the way we take. Since we have installed M school on our laptop, now is the time to have user interface to practice our QCs of the M school. So that is why we're going to install M school work Pinch now. Since we have installed Mce. So as we know that it will be really difficult to learn M school just in the terminal. So that is why we're going to install user interface software for MC, that is basically called M school work Pinch. Okay, what we can do, we can simply write down M SQL download again. And here you have to click on MSchol downloads. And now you'll be able to see the option of MCL community. So we have to click here. So now you can see here, when we're installing M school, we had click on My School community server. So right now we have to install WQinch, so I'm going to simply click here. And here you have to select your operating system. That would be automatically done. And here you can see two options here. So we have the two files here. So the first one is basically for the McBooks that use in tail chip, and the second one is for the Macbooks that use rm chip or the M one or the M two. So I have the Mc with the M one chip. So I'm going to simply download this. And now we have to click on here. And that would simply download our M school work Binge. So we just have to wait a bit for this. All right, so the work pinch is being downloaded. So let's click here, and now we have to click on our work pinch. And now you can see here, what we need to do. We simply have to drag our M school work pinch into the applications. And that was simply install our M school work pinch. So we have installed this. So after this, what we need to do, let's just close this and close this as well. All right. So now what I need to do. I have to click on our M school work pinch. Let's click here. Let's just click on our local instance. So here you have to write down the same password that you have written down when we were installing Mcule. Okay? So you basically have to remember that password. Click on Okay. All right, so I can see this. We are inside our Mice work page, and this is how it looks. So let me try something simple here. So I simply have to write down, show data bases, and I'll just run the QR. And now you can see this. We have our data bases here. So this is how we can install Mikel work pinch. After installing Michel work pinch on our laptop, now we need to learn how can we improve the database. All right, so now our tools are ready. So now we need some data that we can use in our MCL. Okay. So for the data, I'm going to use Gagl. I will get the data from there because they really have a good amount of the datasets that you can use it for the practice. So first, we're going to go there. So you can basically get the data from anywhere that is totally your choice, but I'm going to go here with the Cagle. All right. And I'll simply click here on the data sets. And from here, you'll be able to see a lot of the different data sets here that you can use for the practice on your M school. Why I'm preferring this because each data set has a good amount of the data. So that would really help you to understand the concepts in M school. So here, I'm going to simply go here with all unicorns in the world. So let's click here. I'm going to download this. Okay. So let's click here. All right, so you can see here that we have a list of unicos in the word. We have the CSV file, but sometimes you get the excel file format. Just like this, you can see here, we have cel SX, but sometimes we get the excel sheet form, but then you can simply convert this into the CSV. That is not the problem. Okay. So now what we need to do, we simply open up our work page. And since I've already opened this up, so how can we import our database or how can we import the CSV File Eno M school work Pinch? So the first thing that you need to do, you have to click here on to create a schema that you can see here. So let's click here. So here, I'm going to write down Unicor DB. Schema. All right. Now let's click on Apply and click on apply again. Close this. Now you can see this. We have Unic Schema A. And what is the schema? I think we already know the difference between database and the schema. Okay. Now what we can do to import our CSV file. Let's just do the right click here, and you'll be able to see the option of table data import Viz. Okay, we have to click here, and from here, we have to browse and from here what we need to do. We just have to click on our CSV file. Okay. Let's click here. Click on Open. Now let's click on next. All right, so we're going to create a new table because we don't have any existing table, so let's click on next. All right. So these are the columns that we have in our table. So if you wanted to remove any of these column from here, you can simply uncheck this from here and it won't be included in the table. But I want to include all the columns here. So I'm going to simply click on next and click on next. And this would basically import the data that we have in the CSV file into our table. So let's click on next now. So now you can say this. We have 1233 records imported, so let's click on finish. So now if I click on the tables. All right. So now I'm going to simply open up new SQL file. All right, so now what we can do here. Okay, so the first thing that you need to do whenever you are opening the work pine for the first time. So if you don't know about the databases, what are the databases that you have? What you can do, you'll simply write down, show databases, and you'll use the semi column. And then you'll simply click on this icon here. All right, so you can see here we have successfully imported our unicorn schema. So this is how we can import the database into our M school work page. Now, don't you think that we should start learning about the M school? So the first thing that we're going to learn is, how can we retrieve the data with the select statement? What is select a statement? So select a statement basically help us to retrieve the data from our table. Okay. So consider this that we are having a table in which we have the four columns. And in these highlighted sales, we have our data. All right? So if I wanted to retrieve the data from my table, I will basically use select statement. Okay? So this is the syn text of the select statement. First, you're going to write down select. And after that in the blank, you will basically write down the name of the column that you want to receive from your table. Okay? So you can receive a single column. You can receive the two column, you can receive the three column. In the blank. You will basically write down the name of the columns that you want to see. Okay? So you can basically retrieve the data of one column, two column, three columns, and also all the columns that you have on your table. Okay. So now we're going to learn how to retrieve the data from our table. So the first thing that you need to do, you're going to write down the name of your table. Okay? So for instance, we have the users table. So if I wanted to retrieve the data from all the columns that I have in my table, I will basically use the astik or the star that you can see here. So this will basically give you all the data that you have on your all number of columns. Okay? But if you want to go specific here, if you just wanted to have the data of the name and the e mail, then what you need to do, you'll simply write down the name and the e mail column, and you need to separate them by coma. Then you will only able to see the data of name and e mail. In a similar way, if you just want to get the data of the ID and the phone number, you'll simply write down ID and phone. But one thing that you have to make sure that you have to use the exactly same names of the column in your SQL Qi. All right. So now I'm going to demonstrate you all the things that we have learned now. So now we will demonstrate a select statement in MSc workbench. Before learning to retrieve data with select, we have to learn some basics that we will use in our mice. Okay, the first thing is this, whatever you write down in Mice is considered as a Q. So if I just write down, show data bases, and if I just run this, so this is a kind of a Q. And if I just write down, use. So I want you to use Unicorn schema. And in the last, we will simply use Semicolon. Okay, so this is also a Qi. So if I just run this, now in the M school, we're basically using our unicorn schema. So now, whatever the tables that we have in the Unicorn schema, we can simply use this in our Q. All right. So right now in our schema, we only have a single table, okay? And one thing that you have to remember that in a single database, you can have multiple number of tables, and those tables can have a relationship between each other. Okay? But we're going to talk about that later. But right now, we have to learn how to retrieve the data with select. Okay, so this is our table. You can see this. The name of the table is list of unicorns in the world. Okay. So now what we do, we simply write down. Select a statement. So how do you use the select statement? Is pretty symbol, you'll simply write down select. And after this, you will write down the name of the columns that you want to retrieve. So right now, I want to retrieve all the columns that we have in our table. So for that, we have a symbol that we can use directly without writing down all the column names. That is basically a star or we also call it at the asterk. And after this, what I need to write down, I will write down. From and after this, I will write down the name of the table. Okay? So here, we're going to write down name of the table. So that will be list of unicorns in the world. Okay. So now you can see this. We are actually having an error here. You can see this cross icon here. That is because in our table name, we have the spaces. And that is not a good practice. But since we already have it, now what we can do to access the data from this table, we'll simply use the bates, And now we won't have any issues with it. And now if I just write down a semi column here and run the Qi you'll be able to see our data here. So this is how we can retrieve the data from the table. Okay. So now you can see this. We have these three queries here. The first one is to show databases and the second one in which we are simply using a database. And in the last one, we are retrieving data from a table from the database that we have selected. All right. So one thing you have to make sure is that, how can we separate multiple queries? So we can simply separate them by using Semi column. So if I just don't use a semi column here, you can see this, we are having the error here. So that is why if you want to separate out the multiple queries, you'll use Semi Column. Now, we have to learn about one thing that you can see these two icons here, this one and this one. So we basically use this one to execute a single statement or a single uri. Okay. So how does it decide which query this is going to execute, it basically decide based on your keyboard cursor. So you can see this our keyboard cursor is on the second es statement. And if I put this on the first statement, it will execute this first statement. If I put this on the second one, this will execute the second one, and if I put this onto the third one, this will execute the third one. So now, for example, if I wanted to put this on the second query, and I'll simply click here. And now you'll see our database has been selected. And now if I wanted to see the databases that we have in our Mcle, so I'll simply click on Show databases and click on here. You will be able to see all the databases that we have in our my school. So as we know, this one is used to execute single query, but what if I wanted to execute all the queries together? For that, what we can do, we'll simply click on this one. So I just click on this one. You can see this. It will be executing all of the things. So you can see this, we have the databases here, and we have our data here. Right, let me try to use select statement with a specific number of columns. Okay. So now here, what we're going to learn, if I only wanted to see a specific number of columns in my table. So if I only wanted to see just like the company, the company, and the country. So what I would do, I'll just simply write down company and I'll write down city. And we will have the same sentence here. We can write down from, and after this, we'll write down the name of the table. So let me just copy this from here. And we will use a semi column. All right. So if I just click on this icon now, you'll be able to see each of our QE is executed. The first one show databases, and in the second one, we wanted to see all the number of columns that we have in our table. And in the last one, we actually wanted to see company and the city only. Okay. So that is how we can go here with a specific number of columns. So I I just write down, country here and execute only this query. You'll be able to see we're only having the table with the three columns. So it only executed this last Q. Okay, so now, you know the difference between both of these icons and what is the Q and how can we select all number of columns that we have in our table and also the specific number of columns in our table. But one thing that is bothering me is the name of the table. I would basically like to rename this. Okay? So how can we do this? That is really simple? I will just simply write down rename. Then I will write down the name of the table that we have. Okay, so after writing down the name of the table, I will write down two, and here we're going to write down the new name of the table that we want to have. So that would be simple list underscore Unicorns. Okay? So that would look fine, and we have to add semi coolumn, and we have to do one thing here. I have to add table keyword here. Okay, now we'll only execute this query. So let's select this one and click here. Now you'll be able to see here. Okay. So let me excavate a space here. All right. So now at the last, you can see here, we have renamed the table from list of unicorns in the world to the list unicorns. And you can also see this here in the tables, but you would have to refresh the M school work page, maybe. Okay. So now let's just remove all of these things. I'm going to remove this Qur. We're going to remove this one, this one, and everything from it. And I'll just run this cury. We will basically have the error because we have changed the name of the table. So I have to use the new name here. So that would be List unicorns. All right. So I just run this Qure and now we will have our data. All right, so this is our data. So this is how we can retrieve the data with select statement. After learning to retrieve the data, now we will learn how can we filate the data with a clause? I'm sure that now you have a good understanding of the select statement, and how does it help us to retrieve the data. But one thing that you would have noticed while using select statement that it basically gives you all the data that is available on your table. Now you might be having a question in your mind, then how can I filter the data? So the answer of this question is the clause. So a clause simply helps you to filter the data beast on your conditions. Now, let's imagine that we're having the users table, and we have the four columns in it, and we are having this dummy data into it. Now, what do we want, you want to filter the data. You want to have the specific data based on the conditions. Okay? So for instance, I want you to have the data of the hake. Okay, so how can I do this? But before that, we have to understand the synex of the clause, and where do we use it? So we use the are clause after the name of the table that we use in the select statement. And you would be wondering why we are using the select statement, Because how do we filter the data if we haven't retived the data with a select statement? So are close has to be used with a select statement. It doesn't have any use without it. Okay? So we put the are close after the name of the table. And after the are close, we basically write down the name of the table that we want to use to filter the data. And after that, we simply use the value. Based on that, we want to do the filtration. Okay? So if I wanted to have the data of the Jackie, I'll simply write down the name of the column, that is basically name. And after that, I will simply write down the value. That is in our instance, Jackie. Okay? But one thing you have to notice here that in the select statement, we only wanted to receive the data of name and the e mail. So when we run the uri, we will only be able to receive the name and the e mail of the Jackie. Okay. But if you wanted to have all the data of the Jake, then you will simply use the estic estate of the name of the columns. Okay? So that is how the wear clause work. But if you still have the dows, don't worry. We're going to demonstrate this now in our work bench. I have imported more database here online Fd schema, because I wanted to have the table with some null values. Okay. So how can we filter the data with a clause as we are already familiar with the synex of the are clause? So now, what we need to do? First of all, we have to use the schema, so we're going to write down All right, so we have to run this query. All right. So now what I need to do? I have to write down select star from. Okay. So the table that we have in the Online food schema is online foods. Okay? So we're going to write down online foods. Okay? So let's just run this query, and you will be able to see the data that we have in our table. Okay. So how can we filter the data based on the a clause? So first thing that we have to do, we have to add a clause after the name of the table, and after this, I'm going to put my condition. Okay. So I wanted to select all the people who are single. So I'm going to write down the name of the column. So I will need to add the Betas because we have a space in the name of the column. All right. So where the merital status is equal to single. Okay? We're going to use the semi column. Now let is run this Qury. All right, so I've done a mistake in the name of the column, so that is I have to remove the I here. Now lets run this again. And now you'll be able to see we're only getting the people that are single. So in a similar way, I can simply change the value here to the merit. So let's run this again. And now you'll be able to see only the people whose marital status is merit. So now I wanted to have the people that are basically below than 25 in an age. So I'm going to write down the age here. And here what I would do. Okay. So I'll simply use the less than sine and use 25. So that would simply return all the people that are basically below then 25. Okay? So let's run this query again, and you'll be able to see only the people that are below then 25. Okay, so that is how we can use the were clause to filter the data. Okay, so now we can also get the value of a specified column so. So for example, I would go here with H, and I will go here with gender and then we can go here with occupation. All right. So let's just run this query again. And now we only be able to see the three columns here. So this is how we can use the ad clause. And what we can do here, we can also filter out the data based on null values. Okay, so we can also do the filtration based on the null values. Okay? So how can we do this? So first, I would simply go back here, and I would actually select all the columns and run this again. Okay. So now I wanted to do that I only wanted to get the people whose monthly income is basically null. Okay? So how can you do this? It's really easy. You'll simply write down the name of the column, that is monthly income, and you have to write down is null. Okay? So that will basically return as all the people. Monthly salary is null in our table. Okay? So let's just run this again. And now you can see this. We are getting all the people whose monthly income or the salary is basically null. And I can also do the opposite thing. So if I wanted to get all the values that are not null, so I'm going to simply add not null here, and it will retain us all the people with monthly income. So let's just run this again. All right, so as you can see is we don't have anyone with the monthly income, null. Okay? And there is one more thing that we can do here. We can use inequality sign. So for example, if I just remove this, so for example, I wanted to get the people whose occupation is a student. Okay? So let's just write down occupation is equal to. Student. Let us Run this. And now we will get all the people whose occupation is basically student. But what if, if I wanted to have all the people, whose occupation is basically not a student? So that is where I can simply use inequality sign, and that will return us all the people whose occupation is not a student. So we'll basically get all the values except student. In the occupation column. Let us Run this, And now you'll be able to see that we are getting self employed and employees. We are getting house wive, and you can see this. We are getting all the different values except student. And that is how we can use inequality sign in are close. Okay, so I need to ask you what it tough to filter the data. Now I have something easier for you this time. So now we're going to learn about how to sort the data with order Bi. Since you know how to use the are close, and how can we put the simple condition with it? Now is the time to learn about order by. So basically, it will help you to sort the data. All right. So now, just imagine that we are having our users table. And you can see here that at the top, in the name, we are having Edward. And after this, we are having Michael, and in the last, we are actually having K. So now you can see here that we really don't have the data in the sorted format. Okay. So now we're going to do this with the help of order by. But before that, we have to understand the sent text of the order by. So just like the clause, It will be used after the name of the table that we have in our select statement. So you're going to simply write down order by, and then you'll write down the name of the column. Based on, you want to sort your data. But you have to make sure one thing here that order by can be used along with the close too. So whenever you are using it along with the clause, then it will be used after the clouse. It means that after the name of the table of the select statement, you will write down the close and the condition. And after that, you will write down the order by and the name of the column. You don't have to worry about this. We're going to demonstrate this in the work pinch. Okay. So for our instance, we want you to sort the data by name column. So now, what do I do? I just simply write down the name column after the order by. And before that in the select statement, I can simply choose to see the number of the columns that I want. So for now, I just want to see all the columns here. All right. So when I run this Qury, this will be the result that we will get. Now our data is sorted in the ascending order based on the name column. Okay, now you can see here, the first thing that we have is a gate. After that, we have the Edward, then we have the Marco and the Michael and the Jackie. Okay. So by default, when you use the order by, it sorts the data in the ascending order, but you can also sort this in the descending order. You don't have to worry about this because now we are also going to demonstrate this in our workbench. Okay, we are using Unicorn schema in sorting the data because I think the data that we have in the table and Unicorn schema can actually help us to understand better about sorting data. Okay? St write down our select statement first, all sleet run this. Now you can see this. We have our data of List Unicorn table. So now what we'll do, we'll basically sort the data with order by. Okay. So I'm going to write down order by here. After that, you have to write down the name of the column on which you want to sort the data of the table. So the first thing that I want to do is to sort the data based on numerical column. It simply means the column that has the numerical values. I think I can go here with my unknown column here. I'm going to write down my unknown column, and then what I will do, I just simply run our Qury, and you'll be able to see no difference here. The reason is when we use order by by default, it sorts the data in ascending order. And since we have used unknown column, and you can see this, that was already sorted in ascending order by default. If I wanted to change this into descending order, what I can do here, I'll just simply write down D E S C. And if I just run the Q again, now you'll be able to see we are having our data in descending order based on my unknown column. That was the numerical column that we use, and now what we will use, we'll basically use Alphabetic column. So let's see. I think I would go here with the company. I'm going to write down. Company here and let's just run the query. And now you can see this, we sort the data based on company column in descending order. But if I wanted to have this in ascending order, what I can do here, I can simply remove this. Now it will sort the data in ascending order by default. But if you still wanted to define that, what you'll do, you'll simply write down as C. That simply means you want to sort the data in ascending order. Right now, I'm going to simply remove this. So let just run this query again. And now we can see this, we sort the data by company in ascending order. So that was the idea of order by, and we can also sort the data by using multiple columns. How it's going to work. Let me show you. So the second column that I want to use is basically country. So let's just run this, and it will basically sort the data by company and country column. You won't be able to see so much difference with both of these columns. So that is why I'm going to use country column, and we're going to use CT column, for sorting the data. So that will give you a better understanding. So first, we're going to write down Okay, so let me just remove this, and we're going to write down city here. Okay. But first, let's just go for the country only. So let's run this. Now you can see this, we are having Australia, and you can see this in the city. We are having Sydney, then we are having Melbourne, then we are having Say Hills. So there's no order basically in the city column. But if you want you to have the order, you simply write down City here. So It's just run the Qi again. Now you can see this in Australia, and also in the city, we are having a sending order. Okay. So how does it work when we use two columns to sort the data? So basically, it will just work like this, that it will try to sort the data based on the first column that we have is the country. But when we have the duplicate value in our first column, it will try to sort the data based on the second column. So I can see this in our first column, we are actually having Australia for the multiple times. So that is the duplication of the value. So in such scenario, it will basically sort the data based on the city column. So you can see this, we are having Alexandra, we are having Brisban, we are having Melbourne, and after this, we are having the Richmond and the other cities. So that is how it works. But if I put this in descending order, So now how this going to work. First, it will try to sort the data in ascending order by country. But when we are having the duplicate values in the first column, it will try to sort the data in descending order by city column. So that is how it works when we try to sort the data based on multiple columns. Okay, let's just run this now. And you will see that we are having Sydney now, and after this, we are having Surry Hills then the other values. And now in cities, basically, you are having descending order, and in country, you are having ascending order. But the first value you can see here we are having Argentina, and then we are having the name of the city. That is really difficult to pronounce. Okay. But you can see here that based on the first value, we can see this, it is basically not in any order. But actually, it is working because I told you first it will try to sort the data on the first column. And when we're having the duplicate values in the first column, then it will try to sort the data based on a second column. So that is why you can have a kind of mix of the data on the second column, but that is the idea of it. Okay. So I can also use the descending order in 3. What's Next?: Congratulations on completing the first class of the M school course. And I know now you'd have the solid understanding on the basics of the Micol, and you also might be curious that what we will learn in the next class. So the next class is about the manipulation and the management of the data in the M school. And I will be publishing this really soon or it might already be published at the time when you're watching this video.