David M. Kroenke and David J. Auer Database Processing: F undamentals, Design, and Implementation Chapter Seven: SQL for Database Construction and Application Processing 7-1 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Chapter Objectives To be able to create and manage table structures using SQL statements To understand how referential integrity actions are implemented in SQL statements To be able to create and use SQL constraints To understand several uses for SQL views To be able to use SQL statements to create and use views 7-2 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Chapter Objectives To gain an understanding of how SQL is used in an application program To understand how to create and use triggers To understand how to create and use stored procedures 7-3 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

View Ridge Gallery View Ridge Gallery is a small art gallery that has been in business for 30 years. It sells contemporary European and North American fine art. View Ridge has one owner, three salespeople, and two workers. View Ridge owns all of the art that it sells; it holds no items on a consignment basis. 7-4 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Application Requirements View Ridge application requirements: –Track customers and their artist interests –Record gallery’s purchases –Record customers’ art purchases –List the artists and works that have appeared in the gallery –Report how fast an artist’s works have sold and at what margin –Show current inventory in a Webpage 7-5 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

View Ridge Gallery Database Design 7-6 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

SQL DDL and DML 7-7 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Creating the VRG Database 7-8 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

CREATE TABLE CREATE TABLE statement is used for creating relations. Each column is described with three parts: column name, data type, and optional constraints. Example 7-9 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Data Types: SQL Server 2008 Data Types 7-10 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Data Types: Oracle Database 11g Data Types 7-11 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Data Types: MySQL 5.1Data Types I 7-12 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Data Types: MySQL 5.1Data Types II 7-13 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Constraints Constraints can be defined within the CREATE TABLE statement, or they can be added to the table after it is created using the ALTER table statement. Five types of constraints: –PRIMARY KEY may not have null values –UNIQUE may have null values –NULL/NOT NULL –FOREIGN KEY –CHECK 7-14 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Creating Relationships 7-15 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Implementing Cardinalities 7-16 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Default Values and Data Constraints 7-17 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

SQL for Constraints 7-18 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

ALTER Statement ALTER statement changes table structure, properties, or constraints after it has been created. Example ALTER TABLE ASSIGNMENT ADD CONSTRAINT EmployeeFK FOREIGN KEY (EmployeeNumber) REFERENCES EMPLOYEE (EmployeeNumber) ON UPDATE CASCADE ON DELETE NO ACTION; 7-19 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Adding and Dropping Columns The following statement will add a column named MyColumn to the CUSTOMER table: ALTER TABLE CUSTOMER ADD MyColumn Char(5) NULL; You can drop an existing column with the statement: ALTER TABLE CUSTOMER DROP COLUMN MyColumn; 7-20 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Adding and Dropping Constraints ALTER can be used to add a constraint as follows: ALTER TABLE CUSTOMER ADD CONSTRAINT MyConstraint CHECK ([Name] NOT IN ('Robert No Pay')); ALTER can be used to drop a constraint: ALTER TABLE CUSTOMER DROP CONSTRAINT MyConstraint; 7-21 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Removing Tables SQL DROP TABLE: DROP TABLE TRANS; If there are constraints : ALTER TABLE CUSTOMER_ARTIST_INT DROP CONSTRAINT Customer_Artist_Int_CustomerFK; ALTER TABLE [TRANSACTION] DROP CONSTRAINT TransactionCustomerFK; DROP TABLE CUSTOMER; 7-22 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

SQL DML—INSERT INSERT command: INSERT INTO ARTIST ([Name], Nationality, DateOfBirth, DateDeceased) VALUES ('Tamayo', 'Mexican', 1927, 1998); Bulk INSERT: INSERT INTO ARTIST ([Name], Nationality, DateOfBirth) SELECT [Name], Nationality, Birthdate FROM IMPORTED_ARTIST; 7-23 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

SQL DML—UPDATE UPDATE command: UPDATE CUSTOMER SET City = 'New York City' WHERE CustomerID = 1000; Bulk UPDATE: UPDATECUSTOMER SETAreaCode = '333' WHERE City = 'Denver'; 7-24 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

SQL DML—DELETE DELETE command: DELETE FROM CUSTOMER WHERECustomerID = 1000; If you omit the WHERE clause, you will delete every row in the table KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

JOIN ON Syntax JOIN ON syntax: SELECTCUSTOMER.Name, ARTIST.Name FROMCUSTOMER JOIN CUSTOMER_ARTIST_INT ONCUSTOMER.CustomerID = CUSTOMER_ARTIST_INT.CustomerID JOIN ARTIST ON CUSTOMER_ARTIST_INT.ArtistID = ARTIST.ArtistID; 7-26 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Using Aliases Use of aliases: SELECTC.Name, A.Name FROMCUSTOMER AS C JOIN CUSTOMER_ARTIST_INT AS CI ONC.CustomerID = CI.CustomerID JOIN ARTIST AS A ON CI.ArtistID = A.ArtistID ; 7-27 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

VRG Data—CUSTOMER I 7-28 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

VRG Data—CUSTOMER II 7-29 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

VRG Data—ARTIST 7-30 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

VRG Data CUSTOMER_ARTIST_INT 7-31 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

VRG Data—WORK I 7-32 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

VRG Data—WORK II 7-33 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

VRG Data—TRANS I 7-34 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

VRG Data—TRANS II 7-35 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Outer Joins Left Outer Join: SELECTC.LastName, C.FirstName, A.LastName AS ArtistName FROMCUSTOMER C LEFT JOIN CUSTOMER_ARTIST_INT CI ONC.CustomerID = CI.CustomerID LEFT JOIN ARTIST A ON CI.ArtistID = A.ArtistID; 7-36 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Result of Outer Join 7-37 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

SQL Views SQL view is a virtual table that is constructed from other tables or views. It has no data of its own, but obtains data from tables or other views. SELECT statements are used to define views: –A view definition may not include an ORDER BY clause. SQL views are a subset of the external views: –They can be used only for external views that involve one multivalued path through the schema KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

SQL Views 7-39 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

CREATE VIEW Command CREATE VIEW command: CREATE VIEW CustomerNameView AS SELECTLastName AS CustomerLastName, FirstName AS CustomerFirstName, FROM CUSTOMER; Results: SELECT * FROMCustomerNameView ORDER BYCustomerLastName, CustomerFirstName; 7-40 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Updateable Views 7-41 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Embedding SQL in Program Code SQL can be embedded in triggers, stored procedures, and program code. Problem: assigning SQL table columns with program variables. Solution: object-oriented programming, PL/SQL. Problem: paradigm mismatch between SQL and application programming language: –SQL statements return sets of rows; an application works on one row at a time. Solution: process the SQL results as pseudo-files KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Triggers I A trigger is a stored program that is executed by the DBMS whenever a specified event occurs on a specified table or view. Three trigger types: BEFORE, INSTEAD OF, and AFTER: –Each type can be declared for Insert, Update, and Delete. –Resulting in a total of nine trigger types. Oracle supports all nine trigger types. SQL Server supports six trigger types (only for INSTEAD OF and AFTER triggers) KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Triggers II 7-44 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Firing Triggers When a trigger is fired, the DBMS supplies: –Old and new values for the update –New values for inserts –Old values for deletions The way the values are supplied depends on the DBMS product. Trigger applications include: –Providing default values –Enforce data constraints –Updating views –Performing referential integrity actions 7-45 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

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Stored Procedures A stored procedure is a program that is stored within the database and is compiled when used: –In Oracle, it can be written in PL/SQL or Java. –In SQL Server, it can be written in TRANSACT-SQL. Stored procedures can receive input parameters and they can return results. Stored procedures can be called from: –Programs written in standard languages, e.g., Java, C#. –Scripting languages, e.g., JavaScript, VBScript. –SQL command prompt, e.g., SQL Plus, Query Analyzer KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

Stored Procedure Advantages Greater security as store procedures are always stored on the database server Decreased network traffic SQL can be optimized by the DBMS compiler Code sharing resulting in: –Less work –Standardized processing –Specialization among developers 7-50 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

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Triggers vs. Stored Procedures 7-53 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

David Kroenke and David Auer Database Processing Fundamentals, Design, and Implementation (11 th Edition) End of Presentation: Chapter Seven 7-54 KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

KROENKE AND AUER: DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall 7-55 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 © 2010 Pearson Education, Inc. Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall