Basics of SQL

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Hello, and welcome to the blog. This blog is about some of the very basic concepts of SQL.
The concepts which we are going to talk about are as follows:
  1. What is SQL?
  2. What is Database?
  3. Is Excel sheet a database or not?
  4. What is DBMS?
  5. What is RDBMS?
  6. Different DBMS software available in the market.
Let's start with
1) What is SQL?
  1. Whenever you post anything on Facebook, Instagram or any other social media platform, your data is stored in a database and then retrieved from it then shown to the users.
  2. The Language because of which this can be done is known as SQL.
  3. SQL stands for Structured Query Language.
  4. SQL is also pronounced as "Sequal" so don't get confused.
  5. SQL is used to perform different operation on a database.
  6. With the help of SQL you can perform n number of operations on database right from Creating a database, designing database, inserting data, updating data, retrieving data  and many more.
  7. SQL is not case sensitive language i.e if you write a SQL query in upper case or lower case you will not get an error because of that.
  8. For example: If you write a query  
    1. as "select * from employee" 
    2. or "SELECT * FROM EMPLOYEE" 
    3. or "SeLeCt * FrOm EmPlOyEe" it doesn't matter at all you will get result of query.  
2) What is Database?
  1. "A database is a organized collection of data typically stored electronically on a computer system." this is a standard definition of database.
  2. A database included multiple tables to store data in different format. 
3) Is Excel sheet a database or not?
  1. When we see database for the first time we quickly relate it with excel sheet because it just look very similar.
  2. I want to tell you that excel sheet is not a database. Although they look very similar but excel sheet is not a database.
  3. However we can say that it is an excellent complement to any database as data is added row by row and data is shown in attractive report format but excel is not a database. 
4) What is DBMS?
  1. DBMS stands for "Database Management System", as the name suggests it is used for managing database.
  2. It consists of a group of program which manipulates data and database itself.
  3. It makes it possible for user to update, delete, read, create data and database as well and many other operations can be performed.
  4. A DBMS is responsible for managing 3 most important things : Data, Database Engine and Database Schema. 
    1. Data: Information you want to save or you have saved. 
    2. Database Engine: Allow accessing data, modifying data or I can say to allow manipulation of data. 
    3. Database Schema: It defines overall structure of database.
5) What is RDBMS?
  1. RDBMS stands for "Relational Database Management System".
  2. It allows the user to access data more efficiently as compare to DBMS.
  3. When DBMS was first introduced data used to get stored in file format which was not most effective or efficient way of storing data that's why RDBMS was introduced.
  4. RDBMS stores data in tables.
  5. The biggest advantage of RDBMS is we can structure database in format of logically independent table.
  6. When we add a data in RDBMS system a row is added into a table.
  7. Rows in a database table are also known as tuples and columns of a database table are knows as attributes.
6) Different DBMS software that can be used for creating a database.
  1. There are n number of software available in the market, we are not going to talk about all of them but most popular ones.
  2. Most popular DBMS software's :
    1. My SQL
    2. Oracle
    3. Microsoft SQL Server
    4. SQL Lite
  3. I personally use "Microsoft SQL Server" as I work more on ".net" technologies. If you use ".net Framework" then "Microsoft SQL Server" is most feasible option to go with. Similarly when you use "JAVA" then you go with "Oracle", when you use "php" then you go with "My SQL", when creating a small "Mobile Application" then you go with "SQL Lite".
  4. It is not necessary that if you are working with ".net" then "Microsoft SQL Server" is the only option you can go with any other DBMS software, same goes for other technologies.

Well Done. We have just covered some of basics concepts of SQL. See you  in some another blog till then "Keep coding, keep learning because trust me you can make it big".

"Have a great day".

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