SQL stands for
Structured Query Language, it's a computer language to store, retrieve and query the data from
Multiple Vendors have created their own database software system to store data such as
SQL Server etc, all of them use
SQL or some variation of it as database language.
MySQL is one of the widely used
Relational Database Management Systems (RDBMS). the latest version of
8.29. Community Edition of
MySQL is free and open-source, it can be used for small and large applications.
RDBMS stands for
Relational Database Management System, all
SQL queries run on
RDBMS contains a
tables and the system provides a relation between them.
The core of the storage of
RDBMS is a
table, it consists of
COLUMN, all the data in
RDBMS is actually stored in single or multiple tables.
A row or Record is an individual entry of the table. It's the horizontal entity in the table.
A column is a verticle entity of the table that contains all information of a specific field of a particular row.
SQL commands can be categorized into 4 main groups.
- Data Definition Language
- Data Manipulation Language
- Data Control Language
- Data Query Language
Data Definition Language
Data Definition Language or
DDL is a group of commands which describe the schema or structure of a database or table.
- CREATE : Create command is used to create a new database, a table, or a view of a table in the database
- ALTER : Alter command is used to modify an existing table or column.
- DROP : The drop command is used to delete a database, a table, or a column
Data Manipulation Language
Data Manipulation Language or
DML is a group of commands which can change or manipulate the existing database or table.
- INSERT : Insert command is used to create or insert a new record in the table
- UPDATE : The update command is used to update or modify existing records in the table
- DELETE : Deletes Command is used to delete or remove records from a table
Data Control Language
Data Control Language or
DCL is a group of commands which controls the access of data to the user.
- GRANT : The Grand command is used to give a privilege or permission to the user to access the data
- REVOKE : The Revoke command is used to take the privileges or permissions back from the user
Data Query Language
Data Query Language or DQL is used to query the database and records.
- SELECT : The Select command is used to retrieve the records from single or multiple tables
latest version of
MySQL can be downloaded from https://dev.mysql.com/doc/
Get Information about MySQL
select current user
select the current version of MySQL
select current date
select current time
select the current date-time
select current time
select current timestamp
MySQL query is Letter Case Agnostic, Uppercase and Lowercase both are Valid
MySQL can also be used as a calculator to perform simple calculations such as
SELECT 4 + 1;
to complex mathematical equations such as
SELECT SIN(PI()/4), (4+1)*5;