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SQL - Part 3

SQL from scratch -- Part 3

                                      AND, OR, NOT operators in SQL
In the last part (part -2) we had been spoken about WHERE keyword in SQL, and we did some exercises. It would be better if you had been practiced with keyword which is I wrote in part 1 and 2.
If you know some programming languages, especially Python, then suppose that you are already know about AND, OR, NOT operators. In SQL these operators is used to filter data. Let's look some example.





So given some table ( its name is 'customers')  and in here we want to find People who are not lives in Mexico. How we can do it? Just think about it....

Answer is:


SELECT * FROM customers WHERE NOT Country = 'Mexico';
And if we run this command we can see information about 1st, 4th and 5th rows.
In one sentence:
Note: NOT operator is used for negation of given statement. If we want to find negation of some sentence then don't think a lot about problem j…

SQL - Part 2

SQL tutorial from scratch -- Part 2










                                               WHERE - keyword
In SQL one of the most used keyword is WHERE. This keyword is used for filtering data. For example you are given some big table and you want to find some information. So using WHERE keyword you can easily do these kind of exercises and problems. Let's look more precisely example:
Suppose you live in some region and in this region lives 10000 people. There you want to find information about yourself, so how you can do it? Just think a little....

In Part 1 I already explained SELECT  and FROM keywords. Now using using them try to solve our problem and suppose your id is 212 and table's name is citizens. So we can do something like this:

SELECT * FROM citizens WHERE ID = 212;

When you run this command you can see information about only you.

Let's look another example :


    Note: in this case our table's name is customers




In there we want to choose people…

Flask

                                         Flask




Today we will look at Flask (Which is one of the most popular framework of Python )



Framework is used for to simplify for improving applications. The Python programming language has many frameworks but most popular frameworks are Flask and Django. But Django is used for large scale web applications.
        Django, Flask frameworks is used for developing backend parts of web applications  Maybe you now think "What is backend🤔" 
              Okay in generally web applications divided into two parts 
Frontend -- when we open browser we can see some animations text, headers footer nav-bar and so on. If we collect all of them it would be the frontend part. For developing frontend of web applications you need to know HTML, CSS and JavaScript.

Backend is the backpart of web applications. It means that when you click some button there will be some process. For example you login some page and your information automatically save in dat…

SQL - Part 1

SQL tutorial from scratch -- Part 1


                                                            Introduction


Before going deep dive into in SQL I want to explain the main purpose of DB(database).
Suppose we have large amount of data (for example it would be the students in the same class), and we want to create some website which is give us all information about them. How we do it. Of course using database.Maybe you ask yourself questions: "I can store them in file or array". Yes you is exactly right. But imagine you have large amount of data and if you store them in file or array your program/website will work very hard. Now let's visualize databases:





As we can see it is one of the basic db type which is store title, release_year, length and replacement_cost.

Don't worry about DB if you don't understand them very well. Our next paragraphs will explain it more accurately and also I try to add some important images.






                    "Yes I know that right …

HTML Learning Path

HTML

These are my notes while I learned HTML and I learned it in w3schools.com

First let's look which topics we will learn

1) Introduction     4) Elements      7) Styles            10) Comments 13) Images
2) Editors             5) Attributes     8) Formatting    11)  Colors       14)
3) Basics              6) Headings      9) Quotations    12) CSS            15)









                                                 Introduction

HTML stands for Hyper Text Markup Language. Since it is not programming language.




                                                     Editors

There are a lot of editors depending your computer's operating system.




                                                      Basics

Before explaining each of the tags(you will see more about them next).

                                                      Images Number of page views: