Database Terms

ENTITIES: - Entities are the basic units used in modelling stones of concrete or abstract objects. All such items about which relevant information is stored in the database are called ENTITIES. ENTITY is the identical objects which are transformed from manual to computer system. E.g.  Building, room, chair, transaction, course, machine, employee.

ATTRIBUTES: - The qualities of the entity which we store as information are called the attributes. OR The properties that characterize an entity set are called as attributes. It is also referred as data item, data element, data field, items, elementary item or object property.

DOMAIN: - Each attribute of an entity set has a particular value. The set of possible values that a given attribute can have is called its DOMAIN. Eg. The set of value that the attribute EMPLOYEE. Salary may have take is a positive number ranging between 0.00 and 9,999,999.00.

ENTITY SET               ATTRIBUTES                                 VALUE

EMPLOYEE                          EMPLOYEE.soc_sec_no                               1254

EMPOYEE.Name                                          Amitesh

                                                EMPLOYEE. Address                                   Patna

                                                EMPLOYEE.Desgnation                               System admin

                                                EMPLOYEE. Skill                                         DBA

                                                EMPLOYEE. Salary                                      45056.00