0 0 votes Consider two relations: $$R(A, B), \quad \quad S(E, C)$$Attribute $A$ is the primary key of relation $R$. Attribute $E$ in relation $S$ is a foreign key that references $A$ in $R$.Which of the following operations will NEVER violate the foreign key constraint?Delete a record from $R$ Delete a record from $S$ Insert a record into $R$ Insert a record into $S$ Databases goclasses gate2026_da_memorybased databases data-warehousing multiple-selects one-mark + – GO Classes 283 views answer comment Share Follow Print See 1 comment 1 1 comment reply GO Classes commented Feb 23 reply Follow flag Watch Detailed Video Solution Here! 0 0 replyShare Please log in or register to add a comment.
2 2 votes Answer: (B) Delete a record from S & (C) Insert a record into R Explanation(A) Delete a record from R: This operation can violate the foreign key constraint if the record being deleted from table R has its primary key value referenced by one or more records in table S.(B) Delete a record from S: Deleting a record from the referencing table S does not violate the constraint because it removes a reference to a primary key value in R. The referenced value in R still exists.(C) Insert a record into R: Inserting a new record into the referenced table R does not violate the constraint because it introduces a new primary key value that can be referenced by records in S in the future.(D) Insert a record into S: This operation can violate the foreign key constraint if the value inserted into attribute E (the foreign key) does not already exist as a primary key value in attribute A of table R. BooleanLattice answered Feb 17 BooleanLattice comment Share Follow 0 reply Please log in or register to add a comment.
