1. SQL Views Appendix E DAVID M. KROENKE and DAVID J. AUER DATABASE CONCEPTS, 6 th Edition

2. 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

3. 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 E-3

4. 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 E-4

5. 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 E-5

6. 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 E-6

7. Creating an SQL View: Microsoft SQL Server 2012 KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall E-7 Figure E-1: Creating a View in the Microsoft SQL Server Management Studio

8. 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 E-8 Figure E-2: Creating a View in the Oracle SQL Developer

9. 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 E-9 Figure E-3: Creating a View in the MySQL Workbench

10. 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 EmployeePhoneView ORDER BY LastName; KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall E-10

11. Using the EmployeePhoneView in Microsoft SQL Server 2012 KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall E-11 Figure E-4: Using EmployeePhoneView in the Microsoft SQL Server Management Studio

12. Using the EmployeePhoneView in Oracle Database 11g Release 2 KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall E-12 Figure E-5: Using EmployeePhoneView in the Oracle SQL Developer

13. Using the EmployeePhoneView in Oracle MySQL 5.5 KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall E-13 Figure E-6: Using EmployeePhoneView in the MySQL Workbench

14. 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 E-14

15. Using SQL Views: Hide columns or rows I CREATE VIEW BasicDepartmentDataView AS SELECT DepartmentName, Phone AS DepartmentPhone FROM DEPARTMENT; SELECT * FROM BasicDepartmentDataView ORDER BY DepartmentName; KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall E-15

16. 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 MarkingDepartmentProjectView ORDER BY ProjectID; KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall E-16

17. Using SQL Views: Display results of computations – SQL Statement CREATE VIEW ProjectHoursToDateView AS SELECT PROJECT.ProjectID, Name AS ProjectName, MaxHours AS ProjectMaxHours, SUM(HoursWorked) AS ProjectHoursWorkedToDate FROM PROJECT, ASSIGNMENT WHERE PROJECT.ProjectID = ASSIGNMENT.ProjectID GROUP BY PROJECT.ProjectID; KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall E-17

18. Using SQL Views: Display results of computations – Results SELECT * FROM ProjectHoursToDateView ORDER BY PROJECT.ProjectID; KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall E-18

19. Using SQL Views: Hide complicated SQL syntax – SQL Statement CREATE VIEW EmployeeProjectHoursWorkedView AS SELECT Name, FirstName, LastName, HoursWorked FROM EMPLOYEE AS E JOIN ASSIGNMENT AS A ON E.EmployeeNumber = A.EmployeeNumber JOIN PROJECT AS P ON A.ProjectID = P.ProjectID; KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall E-19

20. 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 E-20

21. Using SQL Views: Layering Computations and Built-in Functions 1 st SQL Statement CREATE VIEW ProjectHoursToDateView AS SELECT PPOJECT.ProjectID, Name AS ProjectName, MaxHours AS ProjectMaxHours, SUM(HoursWorked) AS ProjectHoursWorkedToDate FROM PROJECT, ASSIGNMENT WHERE PROJECT.ProjectID = ASSIGNMENT.ProjectID GROUP BY PROJECT.ProjectID; KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall E-21

22. Using SQL Views: Layering Computations and Built-in Functions 2 nd 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 E-22

23. Using SQL Views: Layering Computations and Built-in Functions Results SELECT ProjectID, ProjectName, ProjectMaxHours, ProjectHoursWorkedToDate, (ProjectHoursWorkedToDate - ProjectMaxHours) AS HoursOverMaxAllocated FROM ProjectsOverAllotedMaxHoursView ORDER BY ProjectID; KROENKE and AUER - DATABASE CONCEPTS (6th Edition) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall E-23

24. SQL Views End of Presentation on Appendix E DAVID M. KROENKE and DAVID J. AUER DATABASE CONCEPTS, 6 th Edition