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CSE 3241 (First Exam (ER (Slides 1, Slides 2), EER (Slides 1, Slides 2),…

- - - - E- R relational mapping
        
        Regular Entity type - map to a relation
        
        one key of the entity type chosen as a primary key for the relation
        
        Weak Entity Type
        
        Include the attributes of the owner relation
        
        primary key is combination of owner key attributes and partial key of weak entity type
        
        Binary M:1 Relationship map to a foreign key in relation
        
        M-side referring to a relation at 1 side
        
        Binary 1:1 relationship
        
        map to a foreign key from one relation referring to the other relation
        
        Binary M:N Relationship
        
        maps to a relation whose primary keys include the keys of both participating relations
        
        Multi Valued Attributes
        
        map to a relation R that includes the key of the owner relation
        
        Each N-ary Relationship
        
        maps to a relation that includes the keys of all participating relations
        
        primary key is the combination of the primary keys of the participating entity
        
        also foreign keys
        
        attributes of the relationship type maps to attributes of the relation
      - EER Model constructs to Relations
        
        Mapping Specialization/Generalization
        
        8a - Any specialization
        
        Create multiple relations for all super/subclasses
        
        8b - subclasses that are total and disjoint
        
        create multiple relations for all subclasses
        
        8c - subclasses are disjoint, with a single special attribute
        
        a single relation with a type attribute
        
        8d - subclasses are overlapping with multiple attributes
        
        create a single relation with multiple type attributes
        
        Mapping of Categories (union types)
        
        9 - Mapping of Union Types (categories
        
        Defining Superclasses have different keys
        
        Specify a new key attribute
        
        Surrogate Key
        
        Summary
        
        Map conceptual schema design in the ER model to a relational database schema
        
        algorithm for ER-to-relational mapping
        
        Illustrated by examples from the COMPANY Database
        
        Include additional steps in the algorithm for mapping constructs from EER model into relational model
      - Relational Database Constraints
        
        Relational Integrity
        
        Domain
        
        Entity
        
        Key
        
        Referential Integrity
        
        Semantic Integrity
        
        Constraint Violations
        
        Insert
        
        Domain
        
        Entity
        
        Key
        
        Referential
        
        Delete
        
        Referential Integrity
        
        Modify
        
        Domain
        
        Entity
        
        Key
        
        Referential Integrity Constraint
        
        Can a Foreign Key have a Null Value?
        
        Deleting Target of a Foreign Key Reference
        
        Restricted
        
        Cascades
        
        Nullifies
        
        Updating Target of a Foreign Key Reference
        
        Restricted
        
        Cascades
        
        Nullfiies
        
        Inserting into Relation with the Foreign Key
        
        Restricted
        
        Cascades
        
        Nullifies
        
        Relation Integrity Constraints