Presentation is loading. Please wait.

Presentation is loading. Please wait.

McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 10 Application Development with Views.

Published byImogene Melton Modified over 8 years ago

Similar presentations

Presentation on theme: "McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 10 Application Development with Views."— Presentation transcript:

1 McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 10 Application Development with Views

2 10-2 Outline  Background  Creating views and using views  Processing queries that reference views  Updatable views  Data requirements for hierarchical forms  Data requirements for reports

3 10-3 What is a View?  Derived table  Behaves like a base table (virtual) with some restrictions for view usage in modification statements  Stored query

4 10-4 View Advantages  Reduce impact of database definition changes  Simplify database usage  Unit of database security  Can be a performance penalty on complex views

5 10-5 Three Schema Architecture

6 10-6 View Definition Example Example 1: Create a view consisting of offerings taught by faculty in the MS department. CREATE VIEW MS_View AS SELECT OfferNo, Course.CourseNo, CrsUnits, OffTerm, OffYear, Offering.FacSSN, FacFirstName, FacLastName, OffTime, OffDays FROM Faculty, Course, Offering WHERE FacDept = 'MS' AND Faculty.FacSSN = Offering.FacSSN AND Offering.CourseNo = Course.CourseNo

7 10-7 Column Renaming Example 2: create a view containing offering data and the number of enrolled students. CREATE VIEW Enrollment_View ( OfferNo, CourseNo, Term, Year, Instructor, NumStudents ) AS SELECT Offering.OfferNo, CourseNo, OffTerm, OffYear, FacLastName, COUNT(*) FROM Offering, Faculty, Enrollment WHERE Offering.FacSSN = Faculty.FacSSN AND Offering.OfferNo = Enrollment.OfferNo GROUP BY Offering.OfferNo, CourseNo, OffTerm, OffYear, FacFirstName, FacLastName

8 10-8 Using Views Example 3 SELECT OfferNo, CourseNo, FacFirstName, FacLastName, OffTime, OffDays FROM MS_View WHERE OffTerm = 'SPRING' AND OffYear = 2003 Example 4 SELECT OfferNo, Instructor, NumStudents, CrsUnits FROM Enrollment_View, Course WHERE Enrollment_View.CourseNo = Course.CourseNo AND NumStudents < 5

9 10-9 Processing View Queries  Materialization  Execute two queries  Large overhead  Preferred in static environments such as data warehouses (Chapter 16)  Modification  Substitute view definition for view references  Execute one query  Incurs little overhead  Not possible for all view queries

10 10-10 View Modification

11 10-11 View Materialization

12 10-12 Modification Examples Example 5: Query using a view SELECT OfferNo, CourseNo, FacLastName FROM MS_View WHERE OffYear = 2006 Example 6: Modified query SELECT OfferNo, Course.CourseNo, FacLastName FROM Faculty, Course, Offering WHERE FacDept = 'MS' AND OffYear = 2006 AND Faculty.FacSSN = Offering.FacSSN AND Offering.CourseNo = Course.CourseNo

13 10-13 Single Table Updatable Views  Support modification statements  Rules for single table updatable views  1-1 correspondence between view rows and base table rows  View includes PK of base table  View includes all required columns  View definition does not have GROUP BY or DISTINCT

14 10-14 Updatable View Examples Example 7: Single table updatable view CREATE VIEW Fac_View1 AS SELECT FacSSN, FacFirstName, FacLastName, FacRank, FacSalary, FacDept, FacCity, FacState, FacZipCode FROM Faculty WHERE FacDept = 'MS' Example 8: View update UPDATE Fac_View1 SET FacSalary = FacSalary * 1.1 WHERE FacRank = 'ASST'

15 10-15 View Update with Side Effects Modify column used in the WHERE condition of a view definition Use WITH CHECK OPTION clause to prevent Example 9: Change the department of rows in the Fac_View1 UPDATE Fac_View1 SET FacDept = 'FIN' WHERE FacSalary > 100000

16 10-16 Multiple Table Updatable Views  No industry standard  Only recently supported  More complex rules than single table updatable views  Access supports flexible view updates for multi-table views  Oracle rules in Appendix 10.B

17 10-17 1-M Updatable Queries  Associated with 1-M relationships  Join column of the parent table: primary key or unique  Determine updatable tables  Child table updatable  Primary key  Foreign key: must include in the query result  Required columns of the child table  Include primary key and required columns to support insert operations on the parent table  Use join operator style

18 10-18 1-M Updatable Query Example Example 10: Save as Course_Offering_View1 SELECT Course.CourseNo, CrsDesc, CrsUnits, Offering.OfferNo, OffTerm, OffYear, Offering.CourseNo, OffLocation, OffTime, FacSSN, OffDays FROM Course INNER JOIN Offering ON Course.CourseNo = Offering.CourseNo

19 10-19 Usage of a 1-M Updatable Query Example 11: Insert a row into the Course_Offering_View1. INSERT INTO Course_Offering_View1 ( OfferNo, Offering.CourseNo, OffTerm, OffYear, OffLocation, OffTime, FacSSN, OffDays ) VALUES ( 7799, 'IS480', 'Spring', 2003, 'BLM201', ' 1:30PM ', '098-76-5432', 'MW' )

20 10-20 Extensions to Multiple Tables  Apply rules to each 1-M relationship  FK of each child table in the query result  Usually only the lowest level child table is updatable  Examples  Course-Offering, Faculty-Offering  Offering-Enrollment, Faculty-Offering

21 10-21 Hierarchical Forms  Formatted window for data entry and display  Main form  Subform  Provide attractive interface for a 1-M relationship  Specification of data requirements is important

22 10-22 Revised University Database

23 10-23 Example Hierarchical Form

24 10-24 Analysis of Data Requirements  Identify the 1-M relationship  Identify the linking fields  Determine other tables in the main form and the subform  Determine updatable tables  Write queries for the main form and subform

25 10-25 Registration Form Requirements  1-M relationship: Registration-Enrollment  Linking fields: Registration.RegNo, Enrollment.RegNo  Other tables  Main form: Student  Subform: Offering, Course, Faculty  Updatable tables: Registration, Enrollment

26 10-26 Registration Main Form Query SELECT RegNo, RegTerm, RegYear, RegDate, Registration.StdSSN, Registration.StdSSN, RegStatus, StdFirstName, StdLastName, StdClass, StdCity, StdState FROM Registration INNER JOIN Student ON Registration.StdSSN = Student.StdSSN

27 10-27 Registration Subform Query SELECT RegNo, Enrollment.OfferNo, OffTime, Offering.CourseNo, OffLocation, OffTerm, OffYear, Offering.FacSSN, FacFirstName, FacLastName, CrsDesc, CrsUnits FROM ( ( Enrollment INNER JOIN Offering ON Enrollment.OfferNo = Offering.OfferNo ) INNER JOIN Course ON Offering.CourseNo = Course.CourseNo ) LEFT JOIN Faculty ON Faculty.FacSSN = Offering.FacSSN

28 10-28 Faculty Assignment Form

29 10-29 Faculty Assignment Requirements  Step 1: Faculty (parent table), Offering (child table)  Step 2: Faculty.FacSSN, Offering.FacSSN  Step 3: Course table in the subform  Step 4: update Offering.FacSSN

30 10-30 Faculty Assignment Queries  Main form SELECT FacSSN, FacFirstName, FacLastName, FacDept FROM Faculty  Subform SELECT OfferNo, Offering.CourseNo, FacSSN, OffTime, OffDays, OffLocation, CrsUnits FROM Offering INNER JOIN COURSE ON Offering.CourseNo = Course.CourseNo

31 10-31 Hierarchical Reports  Stylized presentation of data appropriate to a selected audience  Use nesting (or indentation) to provide a visually appealing layout  Vocabulary  Group: sorted field; usually indented  Detail line: innermost field

32 10-32 Example Hierarchical Report

33 10-33 Summary Data in Detail Lines

34 10-34 Query Formulation Skills  Less difficult than skills for forms  Inspect report  Match fields in the report to database columns  Determine the needed tables  Identify the join conditions  Determine the level of detail  Row data versus summary data  Query should provide data for the detail lines

35 10-35 Faculty Work Load Query SELECT Offering.OfferNo, FacFirstName, FacLastName, FacDept, OffTerm, CrsUnits, OffLimit, Count(Enrollment.RegNo) AS NumStds, NumStds/Offlimit AS PercentFull, (NumStds/Offlimit) < 0.25 AS LowEnrollment FROM Faculty, Offering, Course, Enrollment WHERE Faculty.FacSSN = Offering.FacSSN AND Course.CourseNo = Offering.CourseNo AND Offering.OfferNo = Enrollment.OfferNo AND ( ( Offering.OffTerm = 'Fall' AND Offering.OffYear = 2005 ) OR ( Offering.OffTerm = 'Winter' AND Offering.OffYear = 2006 ) OR ( Offering.OffTerm = 'Spring' AND Offering.OffYear = 2006 ) ) GROUP BY Offering.OfferNo, FacFirstName, FacLastName, FacDept, OffTerm, CrsUnits, OffLimit

36 10-36 Summary  Significant benefits with a modest performance penalty  Foundation of application data requirements  Updatable views important for hierarchical forms  Carefully analyze data requirements before developing forms and reports

37 10-37 Questions & Discussion

Download ppt "McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 10 Application Development with Views."

Similar presentations

Query Formulation with SQL

Query Formulation with SQL
Chapter 8 Normalization. © 2001 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill/Irwin Outline Modification anomalies Functional dependencies.

Chapter 8 Normalization. © 2001 The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill/Irwin Outline Modification anomalies Functional dependencies.
12 CHAPTER DATABASES Databases are the key to accessing information throughout our lives. Used in hospitals, grocery stores, schools, department stores,

12 CHAPTER DATABASES Databases are the key to accessing information throughout our lives. Used in hospitals, grocery stores, schools, department stores,
McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 9 Advanced Query Formulation with SQL.

McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 9 Advanced Query Formulation with SQL.
Relational Model Stores data as tables –Each column contains values about the same attribute –Each column has a distinct name –Each row contains values.

Relational Model Stores data as tables –Each column contains values about the same attribute –Each column has a distinct name –Each row contains values.
McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 6 Developing Data Models for Business Databases.

McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 6 Developing Data Models for Business Databases.
McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 7 Normalization of Relational Tables.

McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 7 Normalization of Relational Tables.
A Guide to SQL, Seventh Edition. Objectives Understand the concepts and terminology associated with relational databases Create and run SQL commands in.

A Guide to SQL, Seventh Edition. Objectives Understand the concepts and terminology associated with relational databases Create and run SQL commands in.
3 / 12 CHAPTER Databases MIS105 Irfan Ahmed Ilyas.

3 / 12 CHAPTER Databases MIS105 Irfan Ahmed Ilyas.
7-1 Normalization - Outline  Modification anomalies  Functional dependencies  Major normal forms  Practical concerns.

7-1 Normalization - Outline  Modification anomalies  Functional dependencies  Major normal forms  Practical concerns.
A Guide to MySQL 7. 2 Objectives Understand, define, and drop views Recognize the benefits of using views Use a view to update data Grant and revoke users’

A Guide to MySQL 7. 2 Objectives Understand, define, and drop views Recognize the benefits of using views Use a view to update data Grant and revoke users’
Chapter 9 Advanced Query Formulation with SQL. Outline Outer join problems Type I nested queries Type II nested queries and difference problems Nested.

Chapter 9 Advanced Query Formulation with SQL. Outline Outer join problems Type I nested queries Type II nested queries and difference problems Nested.
McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 9 Supplemental Slides Type II Nested Query Demonstration.

McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 9 Supplemental Slides Type II Nested Query Demonstration.
Chapter 6 Developing Data Models for Business Databases.

Chapter 6 Developing Data Models for Business Databases.
Chapter 8 Physical Database Design. McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved. Outline Overview of Physical Database.

Chapter 8 Physical Database Design. McGraw-Hill/Irwin © 2004 The McGraw-Hill Companies, Inc. All rights reserved. Outline Overview of Physical Database.
McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 3 The Relational Data Model.

McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 3 The Relational Data Model.
SQL - Part 2 Much of the material presented in these slides was developed by Dr. Ramon Lawrence at the University of Iowa.

SQL - Part 2 Much of the material presented in these slides was developed by Dr. Ramon Lawrence at the University of Iowa.
Copyright 2007, Paradigm Publishing Inc. BACKNEXTEND 3-1 LINKS TO OBJECTIVES Save a Filter as a Query Save a Filter as a Query Parameter Query Inner, Left,

Copyright 2007, Paradigm Publishing Inc. BACKNEXTEND 3-1 LINKS TO OBJECTIVES Save a Filter as a Query Save a Filter as a Query Parameter Query Inner, Left,
With Microsoft Office 2007 Intermediate© 2008 Pearson Prentice Hall1 PowerPoint Presentation to Accompany GO! with Microsoft ® Office 2007 Intermediate.

With Microsoft Office 2007 Intermediate© 2008 Pearson Prentice Hall1 PowerPoint Presentation to Accompany GO! with Microsoft ® Office 2007 Intermediate.
With Microsoft Access 2007 Volume 1© 2008 Pearson Prentice Hall1 PowerPoint Presentation to Accompany GO! with Microsoft ® Access 2007 Volume 1 Chapter.

With Microsoft Access 2007 Volume 1© 2008 Pearson Prentice Hall1 PowerPoint Presentation to Accompany GO! with Microsoft ® Access 2007 Volume 1 Chapter.

Similar presentations

Ads by Google