Business Rules and Data Models
Describe the purpose of the database.
The purpose of a database is collecting interrelated and related data in an order that full information can be accessed easily. It is therefore important to set the programs necessary for the data. Database offers an automated environment that is easy to access and use especially in a challenging environment like in the case of this college. Database management system is used in defining, manipulating, retrieving and managing data in the database. A database management system manipulates generally the data itself, field names, the data format, files structure and record structure. Database management system also defines the rules to manipulate and validate this data. A database management system relieves its users of the framing programs used for data maintenance. DBMS package are used along with forth generation query languages to interact with the database.
Based on your research and / or common knowledge of a college and the information tracked by a college, describe the entities of the database and the attributes of each entity.
Attributes: Student_ID, First_Name, Last_Name, Phone_Number, Year_of_Admission, Cousre_ID
Entity: Course
Attributes: Course_ID, Course_Name, Instructor_ID, Course_Duration
Entity: Instructor
Attributes: Instructor_ID, First_Name, Last_Name, Course_ID, Phone_Number
Based on your research and / or common knowledge of a college and the information tracked by a college, describe the business rules that could impact the structure of the database.
Some of the business rules that can affect the structure of this database include the following:
All students must have an ID
A student can take more than one course
Only authorized persons should access and make changes on the database, password protection should be included
Determine the information that the conceptual model of the database would include and determine the information that the physical model of the database would include.
Information on the conceptual model of the database
A conceptual model identifies highest level relationships among the different entities. The features of a conceptual model include the following;
Important entities and relationships between them
No primary key is specified
No attribute is specified
The information that is included is Entity Name and the Entity Relationship.
Information that the physical model of the database will include
Physical data model shows all the table structures such as column name, column constraints, column data type, foreign key, primary key and also the relationship between tables. Physical data model features include the following:
Foreign keys; used to identify the relationship between tables
Specifications of all the tables and columns
Physical considerations can cause physical model to be a bit different from logical data model.
Denormalization can take place based on the user requirements
Physical data model will differ depending on relational database management system.
The following steps are followed when designing a physical data model
Entities are converted into tables
Relationships are converted into foreign keys
Attributes are converted into columns
Therefore, the information included in the physical model are: Primary keys, Foreign keys, table names, column names, and column data types.
References
Eddins, W. & Crosslin, R. (2000). What not How: The Business Rules Approach to Application Development. Addison-Wesley longman Inc.
Jeffrey A. Fred R et al., (2003). Data Base Management. Benjamin/Cummings Publishing Company.
