ISRO-2018
February 13, 2024ISRO-2018
February 13, 2024ISRO-2018
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Question 15
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In E-R model, Y is the dominant entity and X is a subordinate entity
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If X is deleted, then Y is also deleted
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If Y is deleted, then X is also deleted
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If Y is deleted, then X is not deleted
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None of the above
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Question 15 Explanation:
→ It is the best example of referential integrity. In referential integrity, we are using a foreign key.
→ If we want to delete any entity in the dominant entity(Like primary key of a table) then subordinate entity(derived attribute) also deleted.
Note: If we want to delete any subordinate entity in entity then the dominant entity is not going to delete.
→ If we want to delete any entity in the dominant entity(Like primary key of a table) then subordinate entity(derived attribute) also deleted.
Note: If we want to delete any subordinate entity in entity then the dominant entity is not going to delete.
Correct Answer: B
Question 15 Explanation:
→ It is the best example of referential integrity. In referential integrity, we are using a foreign key.
→ If we want to delete any entity in the dominant entity(Like primary key of a table) then subordinate entity(derived attribute) also deleted.
Note: If we want to delete any subordinate entity in entity then the dominant entity is not going to delete.
→ If we want to delete any entity in the dominant entity(Like primary key of a table) then subordinate entity(derived attribute) also deleted.
Note: If we want to delete any subordinate entity in entity then the dominant entity is not going to delete.