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));
What is advantage of two-way association? Two-way association advantages are following: a) Independent of the classes. b) Useful for existing predefined classes that are
Distributed Database Management System
how to write a in a text and load it on mysql
Define identify relationship? Identifying relationship: An identifying relationship means in which the child table cannot be uniquely recognize without the parent. For exampl
Normal 0 false false false EN-US X-NONE X-NONE
Differance between Open addressing and chaining for collision resolution ? In open addressing , proceeding from the occupied position specified by hash address the program che
What are axioms? Axioms or rules of inference give a simpler technique for reasoning about
What are the ways in which the variable-length records arise in database systems? Storage of many record types in a file. Record types that permit variable lengths for one o
i would like to ask if you will do assignment of database number of words 1500 and how much
The objectives of this assignment are: - to develop skills in the design of database driven applications - to develop skills in applying SQL to implement the relational and
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