Databases can enforce business rules on permissible values by implementing declarative constraints in the database.

Databases can enforce business rules on permissible values by implementing declarative constraints in the database. These include NOT NULL, CHECK, UNIQUE, REFERENTIAL INTEGRITY, and PRIMARY KEY constraints. Why are these so important yet so often ignored by developers? What are the long–term problems when these constraints are not implemented?

Databases can enforce business rules on permissible values by implementingdeclarative constraints in the database. These include NOT NULL, CHECK,UNIQUE, REFERENTIAL INTEGRITY, and PRIMARY KEY...