Integrity Constraints

• Domain Constraints


  1st Integrity Constraints
• Entity Integrity


  2nd Integrity Constraint
• Referential Integrity


  3rd data constraint
• Domain


  is a set of values that can be assigned to an attribute
• Entity Integrity


  ensures that every relation has a valid primary key
• Referential Integrity


  rule that maintains consistency among the rows of two relations.
• Domain definition


  Consists of domain name, meaning, data type, size and allowable values
• Referential Integrity


  The rule states that if there is a foreign key, either each foreign key value must match a primary key value or the foreign key value must be null