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HSCI6348-HealthcareDatabaseManagement_Chapter14-Tagged.pdf

Database Systems: Design, Implementation, and

Management Tenth Edition

Chapter 14 Database Connectivity and Web

Technologies

Objectives

In this chapter, you will learn: • About various database connectivity

technologies • How Web-to-database middleware is used to

integrate databases with the Internet • About Web browser plug-ins and extensions • What services are provided by Web application

servers

Database Systems, 10th Edition 2

Objectives (cont’d.)

• What Extensible Markup Language (XML) is and why it is important for Web database development

• About cloud computing and how it enables the database-as-a-service model

Database Systems, 10th Edition 3

Database Connectivity

• Mechanisms by which application programs connect and communicate with data sources – Also known as database middleware

• Data repository: – Also known as a data source

– Represents the data management application • Used to store data generated by an application

program

• ODBC, OLE-DB, ADO.NET: the backbone of MS Universal Data Access (UDA) architecture

Database Systems, 10th Edition 4

Native SQL Connectivity

• Connection interface provided by database vendors – Unique to each vendor

• Example: Oracle RDBMS – Must install and configure Oracle’s SQL*Net

interface in client computer

• Interfaces optimized for particular vendor’s DBMS – Maintenance is a burden for the programmer

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Database Systems, 10th Edition 6

ODBC, DAO, and RDO

• Open Database Connectivity (ODBC) – Microsoft’s implementation of a superset of SQL

Access Group Call Level Interface (CLI)

– Widely supported database connectivity interface

– Any Windows application can access relational data sources

– Uses SQL via standard application programming interface (API)

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ODBC, DAO, and RDO (cont’d.)

• Data Access Objects (DAO) – Object-oriented API

• Accesses MS Access, MS FoxPro, and dBase databases from Visual Basic programs

– Provided an optimized interface that exposed functionality of Jet data engine to programmers

– DAO interface can also be used to access other relational style data sources

Database Systems, 10th Edition 8

ODBC, DAO, and RDO (cont’d.)

• Remote Data Objects (RDO) – Higher-level object-oriented application interface

used to access remote database servers

– Uses lower-level DAO and ODBC for direct access to databases

– Optimized to deal with server-based databases, such as MS SQL Server, Oracle, and DB2

• Implemented as shared code dynamically linked to Windows via dynamic-link libraries

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Database Systems, 10th Edition 10

ODBC, DAO, and RDO (cont’d.)

• Basic ODBC architecture has three main components: – High-level ODBC API through which application

programs access ODBC functionality

– Driver manager that is in charge of managing all database connections

– ODBC driver that communicates directly to DBMS

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Database Systems, 10th Edition 12

OLE-DB

• Object Linking and Embedding for Database • Database middleware that adds object-oriented

functionality for access to data • Series of COM objects provides low-level

database connectivity for applications • Functionality divided into two types of objects:

– Consumers – Providers

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OLE-DB (cont’d.)

• OLE-DB did not provide support for scripting languages

• ActiveX Data Objects (ADO) provides high-level application-oriented interface to interact with OLE-DB, DAO, and RDO

• ADO provides unified interface to access data from any programming language that uses the underlying OLE-DB objects

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Database Systems, 10th Edition 15

ADO.NET

• Data access component of Microsoft’s .NET application development framework

• Two new features for development of distributed applications: – DataSet is disconnected memory-resident

representation of database

– DataSet is internally stored in XML format • Data in DataSet made persistent as XML

documents

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Database Systems, 10th Edition 17

ADO.NET (cont’d.)

• Specific objects manipulate data in data source – Connection

– Command

– DataReader

– DataAdapter – DataSet

– DataTable

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Java Database Connectivity (JDBC)

• Java is an object-oriented programming language – Runs on top of Web browser software

• Advantages of JDBC: – Company can leverage existing technology and

personnel training

– Allows direct access to database server or access via database middleware

– Provides a way to connect to databases through an ODBC driver

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Database Systems, 10th Edition 20

Database Internet Connectivity

• Web database connectivity allows new innovative services that: – Permit rapid response by bringing new services

and products to market quickly

– Increase customer satisfaction through creation of Web-based support services

– Allow anywhere, anytime data access using mobile smart devices via the Internet

– Yield fast and effective information dissemination through universal access

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Database Systems, 10th Edition 22

Web-to-Database Middleware: Server-Side Extensions

• Web server is the main hub through which Internet services are accessed

• Dynamic Web pages are at the heart of current generation Web sites

• Server-side extension: a program that interacts directly with the Web server – Also known as Web-to-database middleware

• Middleware must be well integrated

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Database Systems, 10th Edition 24

Web Server Interfaces

• Two well-defined Web server interfaces: – Common Gateway Interface (CGI)

– Application Programming Interface (API)

• Disadvantage of CGI scripts: – Loading external script decreases system

performance – Language and method used to create script also

decrease performance

• API is more efficient than CGI – API is treated as part of Web server program

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Database Systems, 10th Edition 26

The Web Browser

• Software that lets users navigate the Web • Located in client computer • Interprets HTML code received from Web

server • Presents different page components in

standard way • Web is a stateless system: Web server does

not know the status of any clients

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Client-Side Extensions

• Add functionality to Web browser • Three general types:

– Plug-ins

– Java and JavaScript

– ActiveX and VBScript

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Client-Side Extensions (cont’d.)

• Plug-in: an external application automatically invoked by the browser when needed

• Java and JavaScript: embedded in Web page – Downloaded with the Web page and activated

by an event

• ActiveX and VBScript: embedded in Web page – Downloaded with page and activated by event

– Oriented to Windows applications

Database Systems, 10th Edition 29

Web Application Servers

• Middleware application that expands the functionality of Web servers – Links them to a wide range of services

• Some uses of Web application servers: – Connect to and query database from Web page

– Create dynamic Web search pages

– Enforce referential integrity

• Some features of Web application servers: – Security and user authentication

– Access to multiple services

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Web Database Development

• Process of interfacing databases with the Web browser

• Code examples – ColdFusion

– PHP

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Database Systems, 10th Edition 33

Extensible Markup Language (XML)

• Companies use Internet to create new systems that integrate their data – Increase efficiency and reduce costs

• Electronic commerce enables organizations to market to millions of users

• Most e-commerce transactions take place between businesses

• HTML Web pages display in the browser – Tags describe how something looks on the page

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Extensible Markup Language (XML) (cont’d.)

• Extensible Markup Language (XML) – Metalanguage to represent and manipulate data

elements

– Facilitates exchange of structured documents over the Web

– Allows definition of new tags • Case sensitive • Must be well-formed and properly nested • Comments indicated with <- and ->

• XML and xml prefixes reserved for XML tags only

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Database Systems, 10th Edition 36

Document Type Definitions (DTD) and XML Schemas

• Document Type Definition (DTD) – File with .dtd extension that describes elements

– Provides composition of database’s logical model

– Defines the syntax rules or valid tags for each type of XML document

• Companies engaging in e-commerce transaction must develop and share DTDs

• DTD referenced from inside XML document

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Database Systems, 10th Edition 38

Document Type Definitions (DTD) and XML Schemas (cont’d.)

• XML schema – Advanced data definition language

– Describes the structure of XML data documents

• Advantage of XML schema: – More closely maps to database terminology and

features

• XML schema definition (XSD) file uses syntax similar to XML document

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XML Presentation

• XML separates data structure from presentation and processing

• Extensible Style Language (XSL) displays XML data – Defines the rules by which XML data are

formatted and displayed

– Two parts: • Extensible Style Language Transformations

(XSLT) • XSL style sheets

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Database Systems, 10th Edition 41

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Database Systems, 10th Edition 43

XML Applications

• B2B exchanges • Legacy systems integration • Web page development • Database support • Database meta-dictionaries • XML databases • XML services

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Cloud Computing Services

• Cloud computing – “A computing model for enabling ubiquitous,

convenient, on-demand network access to a shared pool of configurable computer resources that can be rapidly provisioned and released with minimal management effort or service provider interaction.”

– Potential to become a “game changer”

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Database Systems, 10th Edition 46

Cloud Implementation Types

• Public cloud • Private cloud • Community cloud

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Characteristics of Cloud Services

• Ubiquitous access via Internet technologies. • Shared infrastructure • Lower costs and variable pricing • Flexible and scalable services • Dynamic provisioning • Service orientation • Managed operations

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Types of Cloud Services

• Software as a Service (SaaS) • Platform as a Service (PaaS) • Infrastructure as a Service (IaaS)

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Cloud Services: Advantages and Disadvantages

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SQL Data Services

• Cloud computing data management service • Provides relational data management to

companies of any size • Avoids high cost of personnel/maintenance • Leverages Internet to provide:

– Hosted data management – Standard protocols – A common programming interface

• Could assist businesses with limited information technology resources

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Summary

• Database connectivity: – Ways in which programs connect and

communicate with data repositories

• Database connectivity software known as database middleware

• Database repository also known as data source – Represents data management application used to

store data generated by the program

• Microsoft interfaces are dominant players – ODBC, OLE-DB, ADO.NET

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Summary (cont’d.)

• Microsoft’s Universal Data Access (UDA) architecture – Collection of technologies to access any type of

data source using common interface

• Native database connectivity: interface provided by database vendor – ODBC is Microsoft's implementation of SQL

Access Group Call Level Interface • Allows any Windows application to access

relational data sources using SQL

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Summary (cont’d.)

• OLE-DB adds object-oriented functionality for access to data

• ActiveX Data Objects provide interface with OLE-DB, DAO, and RDO

• ADO.NET is data access component of Microsoft .NET framework

• Java Database Connectivity (JDBC) interfaces with Java applications with data sources

Database Systems, 10th Edition 54

Summary (cont’d.)

• Database access through the Web uses middleware

• On client side of Web browser, use plug-ins, Java and JavaScript, ActiveX, and VBScript

• On server side, middleware expands functionality of Web servers – Links them to wide range of services

• XML provides semantics to share structured documents across the Web – Produces description and representation of data

Database Systems, 10th Edition 55

Summary (cont’d.)

• Cloud computing – Computing model that provides ubiquitous, on-

demand access to a shared pool of configurable resources that can be rapidly provisioned

• SQL data services (SDS) – Cloud computing-based data management

service that provides relational data storage, ubiquitous access, and local management to companies of all sizes

Database Systems, 10th Edition 56

  • Database Systems: Design, Implementation, and Management Tenth Edition
  • Objectives
  • Objectives (cont’d.)
  • Database Connectivity
  • Native SQL Connectivity
  • PowerPoint Presentation
  • ODBC, DAO, and RDO
  • ODBC, DAO, and RDO (cont’d.)
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • OLE-DB
  • OLE-DB (cont’d.)
  • Slide 15
  • ADO.NET
  • Slide 17
  • ADO.NET (cont’d.)
  • Java Database Connectivity (JDBC)
  • Slide 20
  • Database Internet Connectivity
  • Slide 22
  • Web-to-Database Middleware: Server-Side Extensions
  • Slide 24
  • Web Server Interfaces
  • Slide 26
  • The Web Browser
  • Client-Side Extensions
  • Client-Side Extensions (cont’d.)
  • Web Application Servers
  • Web Database Development
  • Slide 32
  • Slide 33
  • Extensible Markup Language (XML)
  • Extensible Markup Language (XML) (cont’d.)
  • Slide 36
  • Document Type Definitions (DTD) and XML Schemas
  • Slide 38
  • Document Type Definitions (DTD) and XML Schemas (cont’d.)
  • XML Presentation
  • Slide 41
  • Slide 42
  • Slide 43
  • XML Applications
  • Cloud Computing Services
  • Slide 46
  • Cloud Implementation Types
  • Characteristics of Cloud Services
  • Types of Cloud Services
  • Cloud Services: Advantages and Disadvantages
  • SQL Data Services
  • Summary
  • Summary (cont’d.)
  • Slide 54
  • Slide 55
  • Slide 56