What are the types of reference, Database Management System

Assignment Help:

What are the types of reference?explain it with suitable examples?

Object oriented language given the ability to refer the object attribute of the type can be referred to the specified type. We can describe the type dept with a field name and a field head which is reference to the type person and a table dept of the type dept as followed

Create type dept(

Name varchar(20),

Head ref(person)scope people

)

Create table dept of dept

The table definition must state that the reverence is derived and must still state a self referential attribute name. When interesting a tuple for dept we can then use

Insert into dept

Values('CS','john')

 


Related Discussions:- What are the types of reference

Define rule that value of foreign key appear in other table, Determine the ...

Determine the rule that a value of a foreign key should appear as a value of some particular table is called a  Ans: Referential constraint.    The rule that a value of a fo

Record based logical models, Record based Logical Models: Use records as th...

Record based Logical Models: Use records as the key data representation components Examples: Relational Model: It shows data as well as relationship between data in the form

Describe in brief about the sequence diagrams, Describe in brief about the ...

Describe in brief about the Sequence Diagrams Sequence diagrams are interaction diagrams which emphasize time ordering of messages. In UML, it is shown as a table which shows

State the two-way associations, Two-way Associations Mostly, associati...

Two-way Associations Mostly, associations are travel in both directions, although not usually with same frequency. There are three approaches for the implementation. In

Logical design part 1, create an e-r diagram usuing graphical dipicted soft...

create an e-r diagram usuing graphical dipicted software that could theoritically be used in resturant application

Properties of a transaction , Properties of a Transaction        A tra...

Properties of a Transaction        A transaction has four main properties. These are: Atomicity Consistency Isolation or Independence Durability or Permanen

Linear commit protocol, With the linear commit protocol, sites are connecte...

With the linear commit protocol, sites are connected in a chain, and the subtransaction at the left-hand end of the chain initiates the protocol. Propose a crash recovery protocol

What is log shipping, What is Log Shipping? Log shipping is the method ...

What is Log Shipping? Log shipping is the method of automating the backup of database and transaction log files on a production SQL server, and then restoring them onto a stand

What are the objectives of advance object design, What are the Objectives o...

What are the Objectives of Advance object design After this unit, you shall be able to: combine three OOAD models to obtain operations on the classes; develop algo

Explain about primary key, Explain about primary key Primary Key: It ...

Explain about primary key Primary Key: It is one of the candidate keys that are taken to be the recognizing key for the entire table. E.g. although there are two candidate ke

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd