Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
An entity type usually has an attribute whose values are distinct for every individual entity in the collection. Such an attribute is known as a key attribute and its values can be used to recognize each entity uniquely.
Strong entity set: The entity types having a key attribute are known as strong entity types or regular entity types.
Attributes
Let us first answer the question:
What is an attribute?
An attribute is a property used to define the specific feature of the entity. So to define an entity entirely, a set of attributes is used.
For example, a student entity may be defined by the student's name, address, age, course, etc.
An entity will have a value for every of its attributes. For example for a specific student the following values can be assigned:
RollNo: 1234
Name: Supriya
Age: 18
Address: B-4, Mayapuri, Delhi. Course: B.Sc. (H)
Consider entity type Employee with attributes empNumber (this is unique), empName, and the year when he/she was hired. An employee can either be a technical employee, a marketing e
An orchestra database consists of the following relations: CONDUCTS (conductor, composition) REQUIRES (composition, Instrument) PLAYS (Player, Instrument) Give the relational
It defines that the tuple in one relation that refers to another relation must refer to an existing tuple in that relation. This constraint is states on two relations (not essentia
Explain several types of constraints that can be specified using CREATE TABLE command. Explain CASCADE and RESTRICT clauses of DROP SCHEMA command? Constraint Description PRIM
Differance between Unordered and ordered file ? Unordered file do no has any sequence although ordered file has arranged in a few sequence and data are assigned in ordered form
What is nested relational model? The nested relational model is an extension of relational model in which domains might be either atomic or relation valued.
During the deletion of a tuple two cases can happen: Deletion of tuple in relation having the foreign key: In this type of case simply delete the desired tuple. For example, in
What are the Issues when Selecting a Database Issues when Selecting a Database Storage space requirement: A database requires about triple storage space of the actua
What is first normal form? The domain of attribute must contain only atomic (simple, indivisible) values.
What is a Name? A user-supplied name is used for identity. This form of identity is used for files in file systems. The user gives every file a name that uniquely identifies it
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd