210 likes | 445 Views
Database Analysis. Preliminary List of Subjects. Introduction Database development process E-R models The Relational Model Physical Database Design SQL Database Application Design Data Warehousing. ERD – Basic Notation. Relationship. ENTITY TYPE. ENTITY TYPE. Relationship.
E N D
Preliminary List of Subjects • Introduction • Database developmentprocess • E-R models • The Relational Model • Physical Database Design • SQL • Database Application Design • Data Warehousing
ERD – Basic Notation Relationship ENTITYTYPE ENTITYTYPE Relationship Relationship ENTITYTYPE ENTITYTYPE Relationship Used In ITEM PRODUCT Uses
ERD - Cardinalities 0..1 (default) ”One” 1 Mandatory One 0..1 Optional One 0..n (default) ”Many” 1..n MandatoryMany 0..n OptionalMany
ERD – Entity Types STRONG WEAK ASSOCIATIVE
ERD – Relationship Types ENTITYTYPE Unary Binary ENTITYTYPE ENTITYTYPE ENTITYTYPE ENTITYTYPE Ternary ENTITYTYPE
ERD – n-aryRelationships ENTITYTYPE ENTITYTYPE ENTITYTYPE ENTITYTYPE ENTITYTYPE ASSOCIATIVE ENTITYTYPE
ERD - Attributes ENTITY NAME EntityAttributes Identifier PartialIdentifier Attribute Optional [Derived] {Multivalued} (Composite, …)
ERD – RelationshipAttributes Attribute ENTITYTYPE ENTITYTYPE ENTITYTYPE ENTITYTYPE ASSOCIATIVE Attribute
Data Modelling • Data namesshould • Relate to business • Bemeaningful • Beunique • Bereadable • Berepeatable • Follow standard syntax, eg. ”Patient FirstName” (<Entity> <Qualifier> <Attribute>)
Entities • Entity ”sources” • Person • Employee, student, patient • Place • Store, Warehouse, State • Object • Machine, Building, Automobile • Event • Sale, Registration, Renewal • Concept • Account, Course, Work Center
Entities • Entity Type vs. EntityInstance • Strong vs. WeakEntity Types
EntityNaming • SingularNoun (plural and aliases i definition) • Specific • Concise • ”Event name” – not activityorprocess
Attribute Types • Identifier • PartialIdentifier • Required (*) • Optional (o) • Derived ([…]) • Multivalued ({…}) • Composite ((…,…))
Relationships • Attribute vs. Relationships • Multiple relationshipsbetweenentity types