David M. Kroenke and David J. Auer Database Processing: SQL for ...

David M. Kroenke and David J. AuerDatabase Processing:Fundamentals, Design, and ImplementationChapter Seven:SQL for DatabaseConstructionand ApplicationProcessingKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-1

Chapter Objectives• To be able to create and manage table structures usingSQL statements• To understand how referential integrity actions areimplemented 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 useviewsKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-2

Chapter Objectives• To gain an understanding of how SQL is used in anapplication program• To understand how to create and use triggers• To understand how to create and use stored proceduresKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-3

View Ridge Gallery• View Ridge Gallery is a small art gallery that hasbeen in business for 30 years.• It sells contemporary European andNorth 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.KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-4

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 appearedin the gallery– Report how fast an artist’s works have soldand at what margin– Show current inventory in a WebpageKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-5

View Ridge Gallery Database DesignKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-6

SQL DDL and DMLKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-7

Creating the VRG DatabaseKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-8

CREATE TABLE• CREATE TABLE statement is used for creatingrelations.• Each column is described with three parts:column name, data type, and optionalconstraints.• ExampleKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-9

Data Types:SQL Server 2008 Data TypesKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-10

Data Types:Oracle Database 11g Data TypesKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-11

Data Types:MySQL 5.1Data Types IKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-12

Data Types:MySQL 5.1Data Types IIKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-13

Constraints• Constraints can be defined within the CREATETABLE statement, or they can be added to thetable after it is created using the ALTER tablestatement.• Five types of constraints:– PRIMARY KEY may not have null values– UNIQUE may have null values– NULL/NOT NULL– FOREIGN KEY– CHECKKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-14

Creating RelationshipsKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-15

Implementing CardinalitiesKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-16

Default Values and Data ConstraintsKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-17

SQL for ConstraintsKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-18

ALTER Statement• ALTER statement changes table structure,properties, or constraints after it has beencreated.• ExampleALTER TABLE ASSIGNMENTADD CONSTRAINT EmployeeFKFOREIGN KEY (EmployeeNumber)REFERENCES EMPLOYEE (EmployeeNumber)ON UPDATE CASCADEON DELETE NO ACTION;KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-19

Adding and Dropping Columns• The following statement will add a columnnamed MyColumn to the CUSTOMERtable:ALTER TABLE CUSTOMER ADD MyColumn Char(5) NULL;• You can drop an existing column with thestatement:ALTER TABLE CUSTOMER DROP COLUMN MyColumn;KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-20

Adding and Dropping Constraints• ALTER can be used to add a constraint asfollows:ALTER TABLE CUSTOMERADD CONSTRAINT MyConstraint CHECK([Name] NOT IN ('Robert No Pay'));• ALTER can be used to drop a constraint:ALTER TABLE CUSTOMERDROP CONSTRAINT MyConstraint;KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-21

Removing Tables• SQL DROP TABLE:DROP TABLE TRANS;• If there are constraints:ALTER TABLE CUSTOMER_ARTIST_INTDROP CONSTRAINTCustomer_Artist_Int_CustomerFK;ALTER TABLE [TRANSACTION]DROP CONSTRAINT TransactionCustomerFK;DROP TABLE CUSTOMER;KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-22

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, BirthdateFROM IMPORTED_ARTIST;KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-23

SQL DML—UPDATE• UPDATE command:UPDATE CUSTOMERSETCity = 'New York City'WHERE CustomerID = 1000;• Bulk UPDATE:UPDATE CUSTOMERSETWHEREAreaCode = '333'City = 'Denver';KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-24

SQL DML—DELETE• DELETE command:DELETE FROM CUSTOMERWHERE CustomerID = 1000;• If you omit the WHERE clause, you willdelete every row in the table.KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-25

JOIN ON Syntax• JOIN ON syntax:SELECT CUSTOMER.Name, ARTIST.NameFROMCUSTOMER JOIN CUSTOMER_ARTIST_INTON CUSTOMER.CustomerID =CUSTOMER_ARTIST_INT.CustomerIDJOIN ARTISTON CUSTOMER_ARTIST_INT.ArtistID =ARTIST.ArtistID;KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-26

Using Aliases• Use of aliases:SELECT C.Name, A.NameFROMONCUSTOMER AS CJOINCUSTOMER_ARTIST_INT AS CIC.CustomerID = CI.CustomerIDJOIN ARTIST AS AON CI.ArtistID = A.ArtistID;KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-27

VRG Data—CUSTOMER IKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-28

VRG Data—CUSTOMER IIKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-29

VRG Data—ARTISTKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-30

VRG DataCUSTOMER_ARTIST_INTKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-31

VRG Data—WORK IKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-32

VRG Data—WORK IIKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-33

VRG Data—TRANS IKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-34

VRG Data—TRANS IIKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-35

Outer Joins• Left Outer Join:SELECT C.LastName, C.FirstName,FROMONA.LastName AS ArtistNameCUSTOMER C LEFTJOINCUSTOMER_ARTIST_INT CIC.CustomerID = CI.CustomerIDLEFT JOIN ARTIST AON CI.ArtistID = A.ArtistID;KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-36

Result of Outer JoinKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-37

SQL Views• SQL view is a virtual table that is constructed from othertables or views.• It has no data of its own, but obtains data from tables orother 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 onemultivalued path through the schema.KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-38

SQL ViewsKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-39

CREATE VIEW Command• CREATE VIEW command:CREATE VIEW CustomerNameView ASSELECTFROM• Results:SELECT *FROMORDER BYLastName ASCustomerLastName,FirstName ASCustomerFirstName,CUSTOMER;CustomerNameViewCustomerLastName,CustomerFirstName;KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-40

Updateable ViewsKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-41

Embedding SQL in Program Code• SQL can be embedded in triggers, stored procedures,and program code.• Problem: assigning SQL table columns with programvariables.• Solution: object-oriented programming, PL/SQL.• Problem: paradigm mismatch between SQL andapplication programming language:– SQL statements return sets of rows; an application works on onerow at a time.• Solution: process the SQL results as pseudo-files.KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-42

Triggers I• A trigger is a stored program that is executed by theDBMS whenever a specified event occurs on a specifiedtable 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 INSTEADOF and AFTER triggers).KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-43

Triggers IIKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-44

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 theDBMS product.• Trigger applications include:– Providing default values– Enforce data constraints– Updating views– Performing referential integrity actionsKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-45

KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-46

KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-47

KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-48

Stored Procedures• A stored procedure is a program that is stored within thedatabase 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 andthey 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 Hall7-49

Stored Procedure Advantages• Greater security as store procedures are alwaysstored 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 developersKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-50

KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-51

KROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-52

Triggers vs. Stored ProceduresKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-53

David Kroenke and David AuerDatabase ProcessingFundamentals, Design, and Implementation(11 th Edition)End of Presentation:Chapter SevenKROENKE AND AUER - DATABASE PROCESSING, 11th Edition© 2010 Pearson Prentice Hall7-54