... where the child entity points to its parent. Rather than the bookstore having the books, the relationship between the entities is expressed the other way around, where the books maintain a foreign ... NULL CHECK (ProductType = 'D'), LengthInMinutes decimal NOT NULL, Format varchar(4) NOT NULL CHECK (Format IN ('NTSC', 'PAL')), FOREIGN KEY (UPC, ProductType) ... push these issues as far down into the data tier as possible, and in the absence of a data architect, this leaves the database developer as the person responsible for balancing the needs of the...