1 - Database Intro

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Unformatted text preview: BUSI 335 Copyright © 2009-10 Y.M. Cheung, William Tan and Carson Woo • Minimum Cardinality: the minimum number of Cardinality the minimum number of 57 BUSI 335 The Three Types of Minimum Cardinality Cardinality BUSI 335 Copyright © 2009-10 Y.M. Cheung, William Tan and Carson Woo Copyright © 2009-10 Y.M. Cheung, William Tan and Carson Woo 58 Data Modeling Notation Modeling Notation 59 BUSI 335 Copyright © 2009-10 Y.M. Cheung, William Tan and Carson Woo 60 In-Class Exercise One Exercise One Representation of Cardinalities Representation of Cardinalities • Draw an ER diagram to represent the following Mandatory one - when min & max both = 1 (1,1) Mandatory many - when min = 1 and max = many (1,N) Optional one - when min = 0 and max = 1 (0,1) Optional many - when many min = 0 and max = many (0,N) description: description: (min, max) max) BUSI 335 ♦ A professor may teach a minimum of zero and a maximum of three classes. ♦ The minimum number of professors required to teach a class is one, as is the maximum number of professors. ♦ A class may contain no students at all or that up to thirty class may contain no students at all or that up to thirty students may be enrolled. ♦ A student must take at least one class but no more than five classes max min min Copyright © 2009-10 Y.M. Cheung, William Tan and Carson Woo 61 You should specify all the elements including entities, attributes relationship types connectivity and cardinality attributes, relationship types, connectivity and cardinality. BUSI 335 From the ER Diagram to the Relational Database Relational Database Copyright © 2009-10 Y.M. Cheung, William Tan and Carson Woo 62 In-Class Exercise Two Exercise Two ER Diagram Database Entities Tables Attributes Columns/Fields One-to-many Primary key to foreign key of the child table Many-to-many 3 tables: 2 parent tables and a linking table BUSI 335 Copyright © 2009-10 Y.M. Cheung, William Tan and Carson Woo Translate the ER diagram in the previous the ER diagram in the previous exercise to the relational database design. 63 You should include all columns and should include a...
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This document was uploaded on 03/04/2014 for the course COMM 335 at UBC.

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