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What does it mean to say that a database displays both entity integrity and referential integrity?...

Question:

What does it mean to say that a database displays both entity integrity and referential integrity? How are each established?


Answers


Referential Integrity means a condition where a foreign key value is having a match in the same table or in ither table where the value is null.THis null value of the foreign key makes it perfect for not to have a corresponding value but the requirement for matching on values which are not null makes it very diffciult to have a improper value.

Entity Integrity means a conditon where all the tuples in a tabla are uniquely identified by their respective primary key.Having a unique value requirement prevents a null primary key value as the null value is not justified as unique.

Both this referential inttegrity and entity integrity are important to a database as they helps to keep the data or the information stores in the system is accurate and also it prevents erros.Entity integry makes sure that there is no redundancy.

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