Data Integrity

Data integrity ensures in which the data entered into the database through the user is checked for it’s correctness and is the data which is supposed to go into the database. Therefore, the data gets automatically  validated  when  it  is  entered  as  per  the  instructions  or  commands  of  the designer and through this way RDBMS ensures which the application is of a high degree of integrity and data security.RDBMS  ensures  data  integrity  by  automatic  validation  of  data  using  integrity constraints. Integrity constraints are non-procedural constructs and through just specifying those and the designer can automate the validation procedure at the time of data entry. Popular integrity constraints are UNIQUE, NOT NULL, FOREIGN KEY PRIMARY KEY and CHECK constraints.

Data integrity described into the following categories which are given below:

-  Entity integrity
-  Domain integrity
-  Referential integrity

Entity integrity

Entity integrity ensures that each row can be uniquely identified through an attribute known as the primary key. A primary key cannot have a NULL value.

Domain Integrity

Domain integrity refers to the range of valid entries for a provided column. It ensures which there are only valid entries in the column.

Referential integrity

Referential integrity are ensures for every value of a foreign key where there is a matching value of the primary key.