Database design / normalization structure needs to contain ANDs, ORs, optional elements and their relationships

Question

I want to store the details of college courses in a (MySql) database but I\'m not sure how to maintain the relationship between modules and selections.

Basically, a cour

Answer 1

You can probably do something like this:

TABLE course_definition (
    ID int,
    num_mandatory_sections int,
    mandatory_hours int,
    num_optional_modules int,
    optional_hours int,
);

TABLE modules (
    ID int,
    Description varchar(max),
    hours int,
    ....
);

TABLE course (
    Course_ID int FOREIGN KEY (course_definition.id),
    module_id int FOREIGN KEY (modules.id)
);

TABLE course_module_relationship (
     Course_ID int FOREIGN KEY (course_definition.id),
     module_ID int foreign key (modules.id),
     Requirement_flag ENUM ("MANDATORY", "OPTIONAL")
);

TABLE Student_to_course (
     Student_ID int,
     Course_ID int foreign key (course_definition.id)
);

TABLE Student_to_module (
     Student_ID int,
     Module_ID int FOREIGN KEY (module.id)
);

If you really need to be able to create group modules aka single module created from the multiple other modules then table module will need to have a flag field:

group_module boolean

and the following table should be added:

TABLE module_groupings (
    group_module_ID int foreign key (module.id)
    dependant_module_id int foreign key (module.id)
);

This is more of pseudo code but you get the idea. The table course and course_module_relationship will have no keys and store your relationships as they can be many to many as I understand the problem. So basically the code that will read process the selections will have to check whether or not this meets the criteria for the course_definition.

If the Mandatory section to Course is a 1-to-1 relationship you can separate your mandatory section into a separate table but you will have to analyze your data more thoroughly.