SQL Commands MySQL Essential Training
In our previous lesson we are learn the basics about how to create, insert and view data inside the table. As we seen in our first lesson the database has the four main functionalities. They are Create, Read, Update and Delete. In this SQL Commands MySQL Essential Training lesson we are going learn how these functions are differ from one another.
These commands can be classified into groups based on their nature:
DDL – Data Definition Language
The Data Definition Language is used to defines the structure of the we are going to use in the future. It ‘ll helps on the topics like Create, Alter and Drop the table.
|CREATE||Creates a new table, a view of a table, or other object in database|
|ALTER||Modifies an existing database object, such as a table|
|DROP||Deletes an entire table, a view of a table or other object in the database|
The above given commands are the commands used in the Data Definition Language. It’ll helps us to define and create our table structure.These commands are common in maximum of RDBMS databases.
DML – Data Manipulation Language
The DML is defines the Data Manipulation Language. This language has the commands to insert, update or delete the data inside the table. These commands are perform only the already existing data in the databases. Lets see what are those commands in SQL Commands MySQL Essential Training.
|INSERT||Insert a row, column or a data in the table|
|UPDATE||Update is used for the modified records we already have inside the table|
|DELETE||Deletes a particular records from the table|
These are the commands we can have inside the DML language category. These SQL commands MySQL Essential Training are applied only on the already existing data.
DCL – Data Control Language
The DCL language is used to set and give permissions on the already or newly created data or the table. In SQL Commands MySQL Essential Training lesson we have some commands to set permissons. Lets see them what can they do for us.
|GRANT||Grant a Permission to Users, Groups to access the data or table|
|REVOKE||Cancel the permission we provide to the users|
The above are some commands basically used in the data control language. We can learn them briefly in the upcoming lessons.
DQL – Data Query Language
The data query language is used to retrieve certain data from one or more tables. We can show or access the data from the table for our purpose at any time in the databases.
|SELECT||Retrieves certain records from one or more tables|
The above all are the various SQL Commands we used in our MySQL for our functionalities. We can take a deep look at each and every commands of these in the upcoming lessons. We hope this will gives you some basic knowledge about the SQL Commands.