Data Manupulation Language (DML) || Data Defination Language (DDL) || Integrity Constrants || Part – 2
Data Manupulation Language (DML) :-
The language for accessing and manupulating the data organized by the approprate data model.
C-Create
R-Retrive
U-Update/Modify
D-Delete
There are two classes of data manupulations language:-
(1) Procedural:- The user specified what data is required and how to get that data.
(2) Declarative (Non Procedural):- The user specified what data is required without specifying how to get the data.
Data Defination Language (DDL) :-
(To Create Database Schema)
It is a language that is used for defining the database schema.
It is also called data storage and defination language because it is specified the storage structure and the access method used.
Integrity Constrants :-
This includes all the conditions which the DBMS must always satisfy.
(i) Domain Constrants-
A domain of possible values must be associated with an attributes.
Example: Integer type value, special character etc..
(ii) Referencial Integrity :-
Sometimes value appearing in one relation for given set of rules also appears for another set of attributes in other relation.
(iii) Assertion:-
It is a condition that the database must always satisfy.
Example: Minimum balance in the account. (Lessthen 500)
(iv) Authorization-
- Read
- Insert
- Update
- Deletion
- AU
- None
- Combination
