What is Data Integrity?

Answer 1

The following categories of the data integrity exist with each RDBMS:

Entity Integrity :
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There are no duplicate rows in a table.

Domain Integrity :
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Enforces valid entries for a given column by restricting the type, the format, or the range of values.

Referential integrity :
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Rows cannot be deleted, which are used by other records.

User-Defined Integrity :
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Enforces some specific business rules that do not fall into entity, domain, or referential integrity.