
- Almost same as English.
- Easy to understand and learn.
- Works with all the RDBMS systems currently available.
- Many tools are available to auto generate SQL.
Let’s take an example:
Select Employ_Name
From Employ
This query will retrieve the names of employee from the table EMPLOY.
Classification of SQL
The SQL is basically divided into three parts.
- Data Definition Language(DDL)
DDL statements are used to build and modify the structure of your tables and other objects in the database.
Let’s take an example:
create table Student
(st_name char (20),
st_add char (30),
st_course char (10),
st_rollno numeric(10),
primary key (st_rollno))
This query will create the table in database with fields St_name, st_add, st_course, st_rollno, and will make the st_rollno primary key of table Student.
- Data Manipulation Language (DML)
- Data Control Language (DCL)
DML is used to retrieve, insert, delete and update data in database.
DCL is a subset of SQL, used to control access to data in a database.




