46 Weak Entity Sets Occasionally, entities of an entity set need “help” to identify them uniquely. Entity set E is said to be weak if in order to identify entities of E uniquely, we need to follow one or more many- one relationships from E and include the key of the related entities...
3 Entity Sets uEntity = “thing” or object. uEntity set = collection of similar entities. wSimilar to a class in object-oriented languages. uAttribute = property of (the entities of) an entity set. wAttributes are simple values, e.g. integers or character strings. 4 E/R Diagrams uIn...