Question
Download Solution PDFFind minimum number of tables required for converting the following entity relationship diagram into relational database?
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFRules for finding a minimum number of tables required for an ER diagram:
1) A strong entity with single or composite attributes requires one table.
2) A strong entity with multivalued attributes requires two tables.
3) In the case of many to many relations between two entities, 3 tables are required.
Explanation:
There is one to many relationships between R1and R2. So, two tables are required for two entities. But, entity R1 contains multivalued attribute B, due to which one table for this is also needed.
Here we have 1 to Many relation so we requires two tables.
Attribute B being multi-valued, we need to remove the multi-valued attribute B to convert the given entity-relationship diagram into a relational database.
As relational database do not allow multi-valued attributes. We have to introduce a new table.
So, the number of tables is as below:
R1
R12R2
A table for B (Multi-valued attribute)
So, a total of 3 tables are required for the given entity relational diagram.
So, option 3 is the correct answer.
Last updated on Jun 6, 2025
-> The UGC NET Exam Schedule 2025 for June has been released on its official website.
-> The UGC NET Application Correction Window 2025 is available from 14th May to 15th May 2025.
-> The UGC NET 2025 online application form submission closed on 12th May 2025.
-> The June 2025 Exam will be conducted from 21st June to 30th June 2025
-> The UGC-NET exam takes place for 85 subjects, to determine the eligibility for 'Junior Research Fellowship’ and ‘Assistant Professor’ posts, as well as for PhD. admissions.
-> The exam is conducted bi-annually - in June and December cycles.
-> The exam comprises two papers - Paper I and Paper II. Paper I consists of 50 questions and Paper II consists of 100 questions.
-> The candidates who are preparing for the exam can check the UGC NET Previous Year Papers and UGC NET Test Series to boost their preparations.