Database Modeling & Design Fourth Edition- P56 ppt

... AC -> BDEGH Combining (1), (2), and (3) 2. AW->B 3. B -> ACF 4. H -> AXY 5. M -> HNPTZ Combining (7) and (8) 6. XY -> M Step 4, merging: 1. AC -> BDEFGH, B -> AC, H -> ... Selected Exercises 6. H -> AXY 7. M -> NZ 8. MN -> HPT Step 1: N is extraneous due to M -> N in (7) 9. XY -> MNP Step 2: eliminate NP from the RHS due to M -> NP from (7,8) Af...

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... Teorey.book Page iv Saturday, July 16, 2005 12:57 PM

Ngày tải lên: 05/07/2014, 05:20

... data modeling and database design techniques is impor- tant for database practitioners and application developers. The database life cycle shows the steps needed in a methodical approach to designing a ... data modeling and logical database design examples throughout this book. In conceptual data modeling, the overriding emphasis is on simplic- ity and readability. The goal o...

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... integrity constraint has become integral to relational database design and is usually implied as requirements for the resulting relational database implementation. (Chapter 5 discusses the SQL ... also be written in another form, using an arrow (->) in a kind of shorthand called a functional dependency. For example: emp-id, project-name -> mgr-id where emp-id is the key (unique...

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... entities. Object-oriented design provides arguably a better way to model this situation [Muller, 1999]. 4.3.4 Example of Data Modeling: Company Personnel and Project Database ER Modeling of Individual ... transitivity Project located-in located-in City City lives-in works-in belongs-to works-on * * * * 1 * * 1 1 1 1 1 Teorey.book Page 59 Saturday, July 16, 2005 12:57 PM 4.3 Conceptual...

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... model is transformed to SQL tables. In summary, the application of the ER model to relational database design offers the following benefits: • Use of an ER approach focuses end users’ discussions ... follow easily from real-world require- ments. 4.4 View Integration A critical part of the database design process is step II(b), the integration of different user views into a unified,...

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... Conceptual Data Model to SQL his chapter focuses on the database life cycle step that is of particular interest when designing relational databases: transformation of the conceptual data model ... conceptual data modeling is an effective early step in relational database development. This contention has been proven to some extent by the widespread commercialization and use of software...

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... Transformation division div_no -> div_name, div_addr div_no -> emp_id department dept_no -> dept_name, dept_addr, mgr_id dept_no -> div_no dept_no -> emp_id employee emp_id -> emp_name, emp_addr, ... The Design of Normalized Tables: A Simple Example 117 4. proj_no -> proj_name, proj_start_date, proj_end_date 5. dept_no -> dept_name, mgr_id 6. mgr_id -> dept_no Our...

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... here). select cust_name, cust_num, credit_level from customer where address = 'Enterprise' and credit_level > 7 order by cust_name asc; customer name customer number credit level Bones ... number. select c.*, o.* from customer as c, order as o where c.cust_num = o.cust_num and c.credit_level < 7 order by cust_no asc; cust. no. cust. name address credit level order no. item...

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... o.cust_num from order as o where o.item_num = any (select i.item_num from item as i where i.price > 1000)); customer name Khan Kirk Scotty Sulu Uhura 3. Which customers have not ordered any ... of SQL (select o.cust_num from order as o, item as i where o.item_num = i.item_num and i.price > 100); customer name Bones 4. Which customers have only ordered items weighing more than 1...

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