11 - Referential Key Integrity Constraint | Easy Explanation With Example | Database GATE/NET/PSU

Опубликовано: 15 Июнь 2019
на канале: CRACK GATE CSE

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This video explains everything about Referential Key Integrity Constraints (Foreign Key Integrity Constraints). This detailed explanation clears that what are the kind of procedures we use with respect to the referenced and referencing relation. as we know that in any relation three operations are very common which are insertion, Deletion and Updation.

In the referenced relation,
1) Insertion does not causes any violation.
2) Deletion may cause violation, therefore there are three procedure to handle it as:
---- On delete no action
---- On delete cascade
---- On delete set null
3) Updation may cause violation, therefore there are three procedure to handle it as:
---- On update no action
---- On update cascade
---- On update set null

In the referencing relation if any violation occurs we simple restrict that operation.

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