SQL Components

 SQL is a comprehensive language that has its own DDL and DML components:

A. DATA DEFINITION LANGUAGE

Data Definition Language (DDL) is used to provide commands for defining relation schemes, deleting relations, and creating indices, among others. DDL is also used to specify additional properties of the data. The storage structure and access methods used by the database system by a set of statements in a special type of DDL called a data storage and definition language. These statements define the implementation details of the database schema, which are usually hidden from the users. The data values stored in the database must satisfy certain consistency constraints.  

DATA MANIPULATION LANGUAGE

The SQL commands that deal with the manipulation of data present in the database belong to DML or Data Manipulation Language and this includes most of the SQL statements. It is the component of the SQL statement that controls access to data and to the database. Basically, DCL statements are grouped with DML statements.

B.  INTERACTIVE DATA MANIPULATION LANGUAGE

 Interactive Data Manipulation Language can be used to insert, delete, and update tuples in a relation.

C. EMBEDDED DATA MANIPULATION LANGUAGE

The embedded form of the DML is used to incorporate SQL statements into programs created using other programming languages.