SQL Views Appendix E DAVID M. KROENKE and DAVID J. AUER DATABASE CONCEPTS, 6 th Edition.
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Transcript of SQL Views Appendix E DAVID M. KROENKE and DAVID J. AUER DATABASE CONCEPTS, 6 th Edition.
SQL ViewsAppendix E
DAVID M. KROENKE and DAVID J. AUER
DATABASE CONCEPTS, 6th Edition
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means,
electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States
of America.
Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
Appendix Objectives
• Learn basic SQL statements for creating views
• Learn basic SQL statements for using views
• Understand the reasons for using views
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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SQL Views• A SQL view is a virtual table that is constructed
from other tables or views.• A view has no data of its own, but uses data
stored in tables or other views.• Views are created using SQL SELECT
statements.• Views are used in other SELECT statements just
as if they were a table. • The SQL statements that create the views may not contain an ORDER BY clause.
• If the results of a query using a view need to be sorted, the sort order must be provided by the SELECT statement that processes the view.
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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SQL CREATE VIEW Statement
• The SQL CREATE VIEW statement is used to create view structures.
CREATE VIEW ViewName AS {SQL SELECT statement};
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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SQL CREATE VIEW Example
CREATE VIEW EmployeePhoneView AS SELECT FirstName, LastName,
Phone AS EmployeePhone FROM EMPLOYEE;
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Creating an SQL View:Microsoft SQL Server 2012
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Figure E-1: Creating a View in the Microsoft SQL Server Management Studio
Creating an SQL View:Oracle Database 11g Release 2
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Figure E-2: Creating a View in the Oracle SQL Developer
Creating an SQL View in:Oracle MySQL 5.5
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Figure E-3: Creating a View in the MySQL Workbench
Using an SQL SELECT Statement
• Once the view is created, it can be used in the FROM clause of SELECT statements just like a table.
SELECT *FROM EmployeePhoneViewORDER BY LastName;
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Using the EmployeePhoneView inMicrosoft SQL Server 2012
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Figure E-4:Using EmployeePhoneView in the Microsoft SQL Server Management Studio
Using the EmployeePhoneView inOracle Database 11g Release 2
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Figure E-5: Using EmployeePhoneView in the Oracle SQL Developer
Using the EmployeePhoneView in Oracle MySQL 5.5
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Figure E-6: Using EmployeePhoneView in the MySQL Workbench
Some Uses for SQL Views
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
• Hide columns or rows• Display results of computations• Hide complicated SQL syntax• Layer built-in functions
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Using SQL Views: Hide columns or rows I
CREATE VIEW BasicDepartmentDataView AS SELECT DepartmentName,
Phone AS DepartmentPhone FROM DEPARTMENT;
SELECT * FROM BasicDepartmentDataViewORDER BY DepartmentName;
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Using SQL Views: Hide columns or rows II
CREATE VIEW MarkingDepartmentProjectView AS SELECT ProjectID, Name AS ProjectName,
MaxHours, StartDate, EndDate FROM PROJECT WHERE Department = 'Marketing';
SELECT * FROM MarkingDepartmentProjectViewORDER BY ProjectID;
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Using SQL Views: Display results of computations – SQL Statement
CREATE VIEW ProjectHoursToDateView ASSELECT PROJECT.ProjectID,
Name AS ProjectName,MaxHours AS ProjectMaxHours,SUM(HoursWorked) AS ProjectHoursWorkedToDate
FROM PROJECT, ASSIGNMENTWHERE PROJECT.ProjectID =
ASSIGNMENT.ProjectIDGROUP BY PROJECT.ProjectID;
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Using SQL Views: Display results of computations – Results
SELECT * FROM ProjectHoursToDateViewORDER BY PROJECT.ProjectID;
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Using SQL Views: Hide complicated SQL syntax – SQL Statement
CREATE VIEW EmployeeProjectHoursWorkedView ASSELECT Name, FirstName, LastName,
HoursWorkedFROM EMPLOYEE AS E JOIN ASSIGNMENT AS A
ON E.EmployeeNumber =A.EmployeeNumber
JOIN PROJECT AS PON A.ProjectID =
P.ProjectID;
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Using SQL Views: Hide complicated SQL syntax – Results
SELECT * FROM EmployeeProjectHoursWorkedView;
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Using SQL Views: Layering Computations and Built-in Functions
1st SQL Statement
CREATE VIEW ProjectHoursToDateView ASSELECT PPOJECT.ProjectID,
Name AS ProjectName,MaxHours AS ProjectMaxHours,SUM(HoursWorked) AS
ProjectHoursWorkedToDateFROM PROJECT, ASSIGNMENTWHERE PROJECT.ProjectID =
ASSIGNMENT.ProjectIDGROUP BY PROJECT.ProjectID;
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Using SQL Views: Layering Computations and Built-in Functions
2nd SQL Statement
CREATE VIEW ProjectsOverAllotedMaxHoursView AS
SELECT ProjectID, ProjectName, ProjectMaxHours, ProjectHoursWorkedToDate
FROM ProjectHoursToDateView WHERE ProjectHoursWorkedToDate > ProjectMaxHours;
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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Using SQL Views: Layering Computations and Built-in Functions
Results
SELECT ProjectID, ProjectName, ProjectMaxHours, ProjectHoursWorkedToDate, (ProjectHoursWorkedToDate
- ProjectMaxHours) AS HoursOverMaxAllocated
FROM ProjectsOverAllotedMaxHoursViewORDER BY ProjectID;
KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall
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SQL ViewsEnd of Presentation on Appendix E
DAVID M. KROENKE and DAVID J. AUER
DATABASE CONCEPTS, 6th Edition