Changes between Version 10 and Version 11 of P2
- Timestamp:
- 01/26/26 23:32:03 (2 weeks ago)
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P2
v10 v11 17 17 and not from arbitrary or intuitive assumptions. 18 18 19 ---20 19 21 20 == Basis for the ER-to-Relational Transformation … … 39 38 the placement of foreign keys is determined by the cardinality of the relationship. 40 39 41 ---42 40 43 41 == Mapping of Entities … … 53 51 This reasoning applies equally to Wedding, Venue, Photographer, Band, Registrar, Event, Guest, and other entities. 54 52 55 ---56 53 57 54 == Mapping of Relationships Based on Cardinality … … 71 68 This directly enforces the cardinality defined in the ER model. 72 69 73 ---74 70 75 71 === Many-to-Many (N:M) Relationships … … 89 85 that the relationship itself has properties and must be modeled as a separate entity. 90 86 91 ---92 87 93 88 === One-to-One (1:1) Relationships … … 108 103 The UNIQUE constraint enforces the 1:1 cardinality explicitly at the database level. 109 104 110 ---111 105 112 106 == Derivation of the Relational Schema … … 125 119 No table exists without a direct conceptual origin in the ER model. 126 120 127 ---128 121 129 122 == Data Integrity as a Consequence of the Model … … 138 131 which would contradict the definition of an entity in the ER model. 139 132 140 ---141 133 142 134 === Referential Integrity … … 152 144 This reflects the dependency relationships already present in the ER model. 153 145 154 ---155 146 156 147 === Business Logic Constraints … … 177 168 independently of application logic. 178 169 179 ---180 170 181 171 == Relational Diagram … … 192 182 [[Image(db_202526z_va_prj_wedding_planner v.2 - project.png)]] 193 183 194 ---195 184 196 185 == DDL and DML Implementation
