combination of two or more fields. For example, the combination of StudentID and CourseID the GRADE table can be the primary key of the GRADE table, which means that a grade is received by a particular student for a specific course. The next step of design of database is to identify and make the relationships between the tables so that you can pull the data together in meaningful ways. A relationship between two tables is implemented by using a foreign key . A foreign key is a field in one table that connects to the primary key data in the original table. For example, ClassroomID in the COURSE table is the foreign key that connects to the primary key ClassroomID in the CLASSROOM table. With this design, not only do we have a way to organize all of the data we need and have successfully related all the table together to meet the requirements, but have also prevented invalid data from being entered into the database. You can see the final database design in the figure below:
GRADE
COURSE
a..ASSROOM
v-
Y student!D ,r Course!D-------
' CourseID
' ClassroomID
/
Y student!D
Course Title
Classroom Type
StudentName StudentMajor Student Email
CourseCapacit y
Grade
ClassroomCapacit y
ClassroomID ~
Tables of the student database
Normalization When designing a database, one important concept to understand is normalization . In simple terms, to normalize a database means to design it in a way that: 1) reduces data redundancy; and 2) ensure data integrity. In the School Database design, the design team worked to achieve these objectives. For example, to track grades, a simple (and wrong) solution might have been to create a Student field in the COURSE table and then just list the names of all of the students there. However, this design would mean that if a student Information Systems for Business and Beyond (2019) pg. 73
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