Syllabus Detail

  • Referential, domain, and entity integrity 11 ATAR, 12 GEN, 12 ATAR


What is Data Integrity?

  • Data integrity refers to the accuracy and consistency of data over its entire lifecylce
  • This is a fundamental concept in Computer Science, as it can make or break an IT system
  • The integrity of data is dependant on many factors, including the influence of data duplication and redundancy
  • In terms of a database; referential, domain and entity integrity are assessed


Referential Integrity

  • Referential integrity states that every foreign key must reference a valid existing value in another table
  • This means that for every record in a normalised database, the linking element (the foreign key) must exist in another record
  • Both the primary and foreign keys must be the same data type and length


Domain Integrity

  • Domain integrity refers to the boundaries that shape the data entered into a database
  • This can be as simple placing a limit on the length of the data item and enforcing a specific data type
  • Domain integrity ensures organisation and validity in a database structure


Entity Integrity

  • Entity integrity is a simple concept that ensures the validity of primary keys
  • The concept states that each primary key must not be NULL (meaning it must contain a value of some sort)
  • It also states that each primary key must be unique, meaning no primary key value may be the same as another primary key value in the same record


Further Research

  1. Read more about Data Integrity from Microsoft here
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