Databases can be organized in many different ways by using different models. The data model of a database is the logical structure of data items and their relationships. There have been several data models. Since the 1980s, the relational data model has been popularized. Currently, relational database systems are commonly used in business organizations with few exceptions. A relational data model is easy to understand and use. In a relational database, data is organized into tables (or relations ). Each table has a set of fields which define the structure of the data stored in the table. A record is one instance of a set of fields in a table. To visualize this, think of the records as the rows (or tuple ) of the table and the fields as the columns of the table. In the example below, we have a table of student data, with each row representing a student record, and each column representing one filed of the student record. A special filed or a combination of fields that determines the unique record is called primary key ( or key ). A key is usually the unique identification number of the records.
Fields (Columns) I
key
I
I
I
I I Student!D
StudentEmail
St udentMajor
StudentName
1234 2345 3456 4567
jsmith@university.edu rjackson@university.edu asun@univ e rsity.edu mbrown@university .edu
Marketing
Jonh Smith
Records ~ (Rows) L
Robert Jackson
MIS
Anne Sun
Accounting
Mary Brown
Finance
Rows and columns in a table
Designing a Database Suppose a university wants to create a School Database to track data. After interviewing several people, the design team learns that the goal of implementing the system is to give better insight into students’ performance and academic resources. From this, Information Systems for Business and Beyond (2019) pg. 71
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