Map objects to a relational database? , JAVA Programming

Due to impedance mismatch between relational technology and object you need to understand the progress of mapping classes (objects) and their relationships to tables and relationships between them in a database. Classes show both behavior and data whereas relational database tables just insert data. Database schemas have keys whereas object schema does not have keys and instead use instance references to implement relationships to other objects.

 

858_Relational Database.png

 

1. Classes map to tables in a way but not directly.

2. An attribute of a class may be mapped to zero or more columns in a database. Not all attributes are consistent.

3. Some attributes of an object are objects itself. This is a recursive relationship where at some point the attribute will be mapped to more columns or zero.

4. In its simple form an attribute maps to a single column whereas each has similar type. When you prepare mapping with different kinds then you will use to be able to convert them back and forth.

 

Posted Date: 7/27/2012 4:51:20 AM | Location : United States







Related Discussions:- Map objects to a relational database? , Assignment Help, Ask Question on Map objects to a relational database? , Get Answer, Expert's Help, Map objects to a relational database? Discussions

Write discussion on Map objects to a relational database?
Your posts are moderated
Related Questions
Write a program called LandThePlane that calculates whether a plane successfully lands or not.   The program begins by prompting (asking) the user for the following details, in th

I want to develop a Chat application for j2me Project Description: We require a chat application for a community website. Skills required: Java, J2ME

A for loop repeats until a specified condition evaluates to false. For for loop the JavaScript is similar to the Java and C for loops. A for statement looks as:  for ([initial-

Outbound Submissions and Tracking: Project Overview: In the current ARISg environment, expedited reports are qualified and distributed electronically to contacts maintaine

If there exist multiple conditions, the switch statement is suggested. It is because only one expression gets evaluated depending on which control jumps directly to the respective

I want Multiplayer Backgammon Game Project Description: We want a multiplayer backgammon as short as well as long one. It should be free and on money also. The games fronted

Prepare Simple spring maven task Project Description: We want a very simple delivery for one of our tasks using Spring STS Maven project. This chat does not have UI interf

What are application softwares? List down the names of three application software's. Definition: Application Software are in which software then can interact directory along

When MalformedURLException and UnknownHostException throws? Ans) When the particular URL is not connected then the URL throws MalformedURLException and If InetAddress? methods g