Database Management System · Unit 4
ER to Relational Mapping
Exam-focused notes for ER to Relational Mapping (Database Management System, BIT202): what the TU syllabus asks and how it has actually been tested, with 2 solved past questions from this unit.
What this unit covers
- Mapping entities to relations
- Mapping one-to-many relationships
- Mapping many-to-many relationships
- Mapping weak entities
- Mapping specialization and generalization
Mapping one-to-many relationships
During ER-to-Relational Mapping, explain with example to map 1: N and N:M relationship into a relation? [5]
In a 1:N relationship, the entity on the N-side (many-side) gets the primary key of the 1-side entity added as a foreign key in its relation. No new relation is created. 1. Create relations for both participating entity types. 2. Identify the entity on the ...
Full solved answer →During ER-to-Relational Mapping, show how you map 1:N and N:M relationship into a relation? [5]
In a 1:N relationship between two entity types, the entity on the N-side (many-side) receives a foreign key that references the primary key of the entity on the 1-side (one-side). 1. Create a relation for each participating entity. 2. Identify the entity on...
Full solved answer →Make Unit 4 stick
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