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!
Explain entity integrity and referential integrity rules within relational model. Show how these are realized in SQL?
Entity Integrity Rule - No primary key value could be null.
Referential Integrity Rule - In referential integrity, it is ensured in which a value which appears in one relation for a given set of attributes also appears for a certain set of attributes within another relation.
In SQL, entity integrity and referential integrity rules are implemented as constraints on the relation known as primary key constraint or reference key constraint corresponding. These constraints can be specified along with relation at the time of creation of the relations or after the creation of the relations through altering the definition of the relations. For instance:
CREATE TABLE DEPT
(DEPTNO NUMBER PRIMARY KEY,
DNAME VARCHAR2(15));
CREATE TABLE EMP
(EMPNO NUMBER PRIMARY KEY,
20
ENAME VARCHAR2(15),
JOB VARCHAR2(10),
DEPTNO NUMBER REFERENCES DEPT(DEPTNO));
You are to write a property management database program that allows a real estate agent to view, add, search, and save property listings. The program is to do the following: 1.
Project: Microsoft Access You have been asked by the ABC Tanning Salon to create a database that can be used to track the salon's customers. You are to create a table in Access
Determine the Strong and Weak Entity Based on the method of foreign key, there might be arise a situation when we have to relate an entity having a primary key of its own and a
Reflects organisational structure: Many organizations are distributed over various locations. If an organisation has many offices in dissimilar cities, databases used in such an ap
What are the various symbols used to draw an E-R diagram? Explain with the help of an example how weak entity sets are represented in an E-R diagram. Various symbols used to d
What is NULL? Simply NULL means not in value.
multiplicity constarin
What is relational model feature? A relational model feature is much more data independence than some other database models.
Illustrate the view of software architecture A model is a semantically closed abstraction of system composes of elements. It can be visualized using any of the following five v
Explain hash file organization? Hash functions a) The distribution is uniform Hash functions assign each bucket the similar number of search -key values from the set of a
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