What is SQL?

SQL, short for Structured Query Language, is a database application.

These are the names given to the management systems of databases with different formats and different functions. With SQL it is possible to manage, delete, activate and work on data.

Although it is not a programming language, it is perceived and known as a language by most people. However, it is literally a sub-language that can be used in the database.

So let’s learn some basic sql commands!

Basic SQL Commands

1- Let’s create a database called ‘‘myfirstdatabase’’ with SQL:

* CREATE DATABASE myfirstdatabase;

2-Now let’s create a table called my first table with SQL:

* CREATE TABLE myfirsttable;

3-Let’s add the name, surname, number fields to our table with SQL:

* ALTER TABLE myfirsttable ADD (name VARCHAR(15), surname VARCHAR(20), number INT(11));

4-Let’s put the data named Şeymanur in the name field, Osmanoğlu in the surname field, and 12345 in the number field in our table with SQL:

* INSERT INTO myfirsttable (name, surname, number) VALUES (‘Şeymanur’, ‘Osmanoğlu’, 1234);

5-Let’s list all the data in the table called ‘myfirsttable’ on the screen with SQL:

* SELECT * FROM myfirsttable;

6-Now let’s just list the number field with SQL:

* SELECT number FROM myfirsttable;

Now let’s assume that we have entered many fields and data in our table with the help of “INSERT INTO”.

7-Let’s list the data of people whose name is ‘Ceren’ with SQL:

* SELECT * FROM myfirsttable WHERE name = ‘Ceren’;

8- Let’s list the people whose name is ‘Ceren’ and whose number is 1 with SQL:

* SELECT * FROM myfirsttable WHERE name = ‘Ceren’ and number = 1;

9-Let’s list the data of people whose number starts with 123 with SQL:

* SELECT * FROM myfirsttable WHERE number LIKE ‘123%’;

10-Let’s list those with the letter b in their surname with SQL:

* SELECT * FROM myfirsttable WHERE surname LIKE ‘%b%’;

11-Let’s list the numbers between 15 and 100 with SQL:

* SELECT * FROM myfirsttable WHERE number<100 and number>15;

12-Let’s delete people whose name is Mehmet from our table with SQL;

* DELETE FROM myfirsttable WHERE name=’Mehmet’;

Now I will briefly talk about what some commands do:

*SELECT : Retrieves data from the database.

*INSERT : Adds new data to the database.

*UPDATE : Updates the data in the database.

*DELETE : Deletes the data in the database.

*CREATE : Creates a database or a table within a database.

*ALTER : Updates a database or table.

*DROP : Deletes a database or table.

*GRANT : Used to authorize a user.

*REVOKE : It is used to take back the authorization given to a user.

• That’s all I’m going to talk about SQL briefly. I hope I have helped. Happy coding :D