M:M to 1:M conversion

• What does the course_id column represent in the StudentCourses table?

  The unique ID of a course
• What does the student_id column represent in the StudentCourses table?

  The unique ID of a student
• How does the StudentCourses table maintain the one-to-many relationship?

  Each student can have many courses listed
• What type of relationship does the intermediary table help to create?

  One-to-many relationships
• What does an m:m relationship involve?

  Two tables referring to each other many times
• What is the purpose of creating an intermediary table in a database?

  To change many-to-many relationships to one-to-many
• What is the purpose of the intermediary table in a 1:m relationship?

  To link students to courses one-to-many
• What does the foreign key course_id reference in the StudentCourses table?

  It references the Courses table
• What are the key attributes of an m:m relationship in databases?

  • Involves two tables
  • Each table can have multiple references
  • Requires an intermediary table for conversion to 1:m
• How do we convert an m:m relationship to 1:m?

  By creating an intermediary table
• What is the name of the intermediary table connecting students and courses?

  StudentCourses
• How do the values in the StudentCourses table relate to the Students and Courses tables?

  They point back to their primary keys
• What are the two columns in the StudentCourses table?

  student_id and course_id
• What is the name of the relationship shown in the image?

  Many to many relationship
• What are the advantages of using a many-to-many relationship in this scenario?

  • Allows for more flexibility and scalability in the data model
  • Avoids data duplication and redundancy
  • Simplifies queries and data management
• How would the StudentCourses table look if student 101 is taking courses 201 and 202?

  • student_id: 101, course_id: 201
  • student_id: 101, course_id: 202
• What are the attributes of the course entity?

  id, course_name
• What relationship does adding foreign keys maintain between students and courses?

  It maintains a one-to-many relationship
• What are the two entities shown in the image?

  student and course
• What does the foreign key student_id reference in the StudentCourses table?

  It references the Students table
• What are the attributes of the student entity?

  id, student_name
• What is the purpose of adding foreign keys in the intermediary table?

  To link it with the original tables
• How would you represent this many-to-many relationship in a database?

  • Create a junction/bridge table with the connecting attributes (student_id and course_id)
  • This allows a student to be enrolled in multiple courses and a course to have multiple students
• What are the values of course_id in the StudentCourses table?

  201 and 202
• What is the structure of a new intermediary table in a relational database?

  • Contains foreign keys from both related tables
  • Each foreign key represents a relationship
  • May include additional attributes relevant to the relationship
• What are the connecting attributes between the student and course entities?

  • student_id
  • course_id
• What type of relationship is established between Student and Course after the adjustment?

  One-to-many (1:m)
• What is the name of the intermediary table used in the 1:m relationship?

  Student_Course
• What does the table independence mean in this context?

  There is no direct connection between Student and Course tables
• What was the relationship type between Student and Course before the adjustment?

  Many-to-many (m:m)
• What are the disadvantages of using a many-to-many relationship in this scenario?

  • Increased complexity in the data model
  • More tables to manage and maintain
  • Potential performance issues with complex queries
• What is the significance of maintaining independence between Student and Course tables?

  It allows for more flexible data management
• What does the term "foreign keys" refer to in this context?

  Keys used to link tables together
• What happens to the direct link between Student and Course tables?

  It is removed to maintain independence
• How do the Student and Course tables connect after the adjustment?

  Through the intermediary table using foreign keys
• What are the implications of maintaining table independence in a database?

  • Reduces redundancy
  • Enhances data integrity
  • Allows for easier updates
  • Supports scalability
• What is the purpose of the intermediary table in the relationship between Student and Course tables?

  To link Student and Course tables
• Why is it important to verify the new 1:m relationships?

  To ensure accurate representation of data
• What changes occur in the relationship between Student and Course tables before and after the adjustment?

  • Before: Direct link (m:m)
  • After: Indirect link (1:m) through Student_Course
• How does the intermediary table facilitate the 1:m relationship?

  It allows multiple entries for students and courses