Explain various types of Relational constraints.

Explain various types of Relational constraints.
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Answer :

Relational Constraints Relational constraints are a set of rules. It is used to maintain the quality of information. Integrity constraints ensure that the data insertion, updating, and other processes have to be performed in such a way that data integrity is not affected. Thus, integrity constraint is used to guard against accidental damage to the database.

Types of Relational integrity Constraints are as follows

1. Domain constraints

2. Entity integrity constraints

3. Referential Integrity Constraints

Domain Constraint - It is used to maintain value according to user specification

For example: Not null, check constraint.

Entity integrity constraints –it provides a way of ensuring that changes made to the database by authorized users do not result in a loss of data consistency.

For example: Primary key, unique constraints

Referential Integrity Constraints – It establishes parent child relationship between two tables.

For example :Foreign key constraints 
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