Transcript PowerPoint Chapter 14_1

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Chapter 14
Database Connectivity and Web Development
Database Systems:
Design, Implementation, and Management, Seventh
Edition, Rob and Coronel
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In this chapter, you will learn:
• About the different database connectivity
technologies
• How Web-to-database middleware is used to
integrate databases with the Internet
• The first steps in building a Web-based database
front end using Macromedia ColdFusion
• What Extensible Markup Language (XML) is and why
it is important for Web database development
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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Database Connectivity
• Refers to mechanisms through which
application programs connect and
communicate with data repositories
• Database connectivity software is also known
as database middleware
• Data repository, also known as data source,
represents the data management application
that will be used to store data generated by
application program
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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Native SQL Connectivity
• Refers to connection interface that is
provided by database vendor and is unique to
that vendor
• Best example of that type of native interface
is Oracle RDBMS
– To connect client application to Oracle
database, you must install and configure
Oracle’s SQL*Net interface in client computer
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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Native SQL Connectivity (continued)
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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ODBC, DAO, and RDO
• Open Database Connectivity (ODBC)
– Microsoft’s implementation of a superset of
SQL Access Group Call Level Interface (CLI)
standard for database access
– Probably most widely supported database
connectivity interface
– Allows any Windows application to access
relational data sources, using SQL via
standard application programming interface
(API)
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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ODBC, DAO, and RDO (continued)
• Data Access Objects (DAO)
– Object-oriented API used to access 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: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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ODBC, DAO, and RDO (continued)
• 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
– Was optimized to deal with server-based
databases, such as MS SQL Server, Oracle,
and DB2
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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ODBC, DAO, and RDO (continued)
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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ODBC, DAO, and RDO (continued)
• 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
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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ODBC, DAO, and RDO (continued)
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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ODBC, DAO, and RDO (continued)
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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OLE-DB
• Object Linking and Embedding for Database
• Database middleware that adds object-oriented
functionality for access to relational and nonrelational
data
• Composed of series of COM objects that provide lowlevel database connectivity for applications
• OLE-DB model is better understood when you divide
its functionality into following types of objects:
– Consumers
– Providers
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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OLE-DB (continued)
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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OLE-DB (continued)
• OLE-DB did not provide support for scripting
languages
• ActiveX Data Objects (ADO) provides highlevel 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
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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OLE-DB (continued)
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OLE-DB (continued)
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ADO.NET
• ADO.NET is data access component of Microsoft’s
.NET application development framework
• Introduced two new features critical for development
of distributed applications: DataSets and XML
support
– DataSet is disconnected memory-resident
representation of database
– DataSet is internally stored in XML format and data in
DataSet can be made persistent as XML documents
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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ADO.NET (continued)
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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ADO.NET (continued)
• ADO.NET comes with two standard data providers:
– Data provider for OLE-DB data sources
– Data Provider for SQL Server
• No matter data provider, it must support set of
specific objects in order to manipulate data in data
source
–
–
–
–
–
–
Connection
Command
DataReader
DataAdapter
DataSet
DataTable
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Internet Databases
• Web database connectivity allows new
innovative services that:
– Permit rapid response to competitive
pressures by bringing new services and
products to market quickly
– Increase customer satisfaction through
creation of Web-based support services
– Yield fast and effective information
dissemination through universal access from
across street or across globe
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel
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Internet Databases (continued)
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Web-to-Database Middleware:
Server-Side Extensions
• Also known as Web-to-database middleware
• Program that interacts directly with Web
server to handle specific types of requests
• Provides its services to Web server in way
that is totally transparent to client browser
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Web-to-Database Middleware:
Server-side Extensions (continued)
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Web Server Interfaces
• Two well-defined Web server interfaces:
– Common Gateway Interface (CGI)
– Application programming interface (API)
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