CHAPTER 2 : ENTITY RELATIONAL MODEL

July 8, 2014  |  By  | 


CANDIDATE KEY PRIMARY KEY FOREIGN KEY • An attribute or group of attributes that identifies a unique row in a relation • One of the candidate keys is chosen to be the primary key • Any of the candidates that is selected to be the key or an attribute that uniquely identifies each row in a relation • An attribute in one table whose values must match the primary key in another table or whose must be null SHAMSIAH_DEC12 RELATION KEYS

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