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
What is image processing? It field of computer whereas we enhance and manipulate the graphics. Like it is used to recover old photograph and through processing we can revive

Separating your business logic with other functionality such as services, Loggers etc, making classess more cohesive.

Website for swapping/selling books Project Description: Seeking a website where students can sell and buy books. I want them to swap books as well. Payment options are requir

1. De normalizes your tables where required. 2. Proper use of index columns: An index based on numeric parts is more efficient than an index based on character columns. 3. Re

To change c code and place into a java application Project Description: To change c code and place into a java application Skills required are C Programming, Java, Softwar

what will be the logic? in C program #include float start_point, /* GLOBAL VARIABLES */ end_point, total_area; int numtraps; m


i don''t need any code i need analysis and design only -i need 4 use cases - description - activity diagram -sequence diagram -class diagram - data base diagram

Explain the library java.lang.Math ? The Java class library is huge. We will not cover it all presently. In fact, the remaining eight classes will focus mostly on the class lib

Diffentiate Local and Global Variables? Local or function level variable effective just in the function in that they are declared although global variables visible everywhere o