What is SQL

SQL Oracle Database
SQL

SQL stands for structure query language.SQL accepted as the standard RDBMS language. It is use to interact with the database. In other word we can say it works as a bridge between database and the application. For example If we want to get some data from the table or we want to update some data into the table we need to write some query and for the query we have certain types of statements for that which is as follows.

  1. Data Definition Language(DDL)
  2. Data Manipulation language(DML)
  3. Data Control Language(DCL)
  4. Transaction Control Language(TCL)
SQL Has four commands DDL, DML, DCL, TCL
SQL Commands

 

What is DDL: It deals with table structure. We can say its use for create, alter and drop the table.

We use following command: – create, alter, drop, truncate.


What is DML: it deals with data of the table. Or we can say if we want to do something with the data like insert update delete we perform DML operations.

We use following command: – insert, update, delete.


What is DCL: it deals with privilege. In other word we can say it is use to manage the security of our database, or we can say if we want to give some privilege or get back some privilege from user we perform DCL operations.

We use following command: – grant and revoke.


What is TCL: it deals with save or un-save the data. In short we can say it is use to save the data permanent or un-save the data.

We use following command: – commit, rollback, savepoint