Multivalued attributes, Database Management System

For every multivalued attribute 'A', we make a new relation R that contains an attribute corresponding to plus the primary key attribute k of the relation that shows the entity type or relationship type that has as an attribute. The primary key of R is then mixture of A and k.

For instance, if a STUDENT entity has RollNo, Name and PhoneNumber where phone number is a multi-valued attribute then we will make a table PHONE (RollNo, Phone-No) where primary key is the combination. Please also reminder that then in the STUDENT table we need not have phoneNumber, instead it can be easily (Roll No, Name) only.

Posted Date: 3/6/2013 6:28:26 AM | Location : United States







Related Discussions:- Multivalued attributes, Assignment Help, Ask Question on Multivalued attributes, Get Answer, Expert's Help, Multivalued attributes Discussions

Write discussion on Multivalued attributes
Your posts are moderated
Related Questions
A constraint named less_than_20 was defined on the field date_of_birth of table student. Delete this constraint. ALTER TABLE student DROP CONSTRAINT less_than_20;

Dirty Reads: T10 reads a value which is updated by T9. This update has not been committed and T9 aborts. T9 T10 Value of x old value = 200

Let consider the given partial relation EMP. Let us make some sub-queries for them EMPNO ENAME JOB SAL DEPTNO 7566

what is attribute is attribute inheritance in dbms?

WHERE and HAVING clause in SQL ? The WHERE clause is commonly used for implementing conditions on each tuple of the relation. The HAVING clause is used in combination along wi

Determine the language that needs a user to specify the data to be retrieved with no specifying exactly how to get it is Ans: Non-Procedural DML

When a function module is activated syntax checking is performed automatically. YEs, a function module is activated syntax checking.

What is Asterisk in SQL? Asterisk (*): In SQL, the columns for all the tables and views in the FROM clause will be displayed.

What are the properties of transaction? There are three properties of transactions :- A)     Atomicity B)      Consistency C)       Isolation

Explain the term High level DML? High level DML A high-level or non-procedural DML permit the user to specify what data is needed without specifying how it is to be acquired.