Author Question: To discover the right concepts for domain analysis, we must gather information from ________. A) ... (Read 75 times)

big1devin · **on:** Jul 7, 2018

To discover the right concepts for domain analysis, we must gather information from ________.

A) interviews
B) legacy systems
C) documentation
D) all of the above

Question 2

Describe object-relational mapping. What are the steps and what is the major difference between relational modeling and a pure object-oriented database?

What will be an ideal response?

kingdude89 · **Reply #1 on:** Jul 7, 2018

Answer to Question 1

D

Answer to Question 2

In object-relational mapping we use a software layer that mediates between object-oriented languages and relational DBMSs. Mapping to a relational database is the application of relational and normalization rules to classes and their relationships.
The following are the general steps that should be followed to transform an object-oriented model into a relational one. Entity classes form the majority of tables. Class attributes become table attributes (or columns). A table must have a primary key. Repeating attributes must be separated into tables. Associations are mapped by a primary-foreign key pairs. Multiplicity is mapped through foreign keys. To map to a relational database, aggregation must be flattened into association. In the inheritance chain, only classes with non-derived attributes are selected for mapping.
The major difference is that object-oriented model allows repeating attributes and the relational model does not.