INF3703 - Chapter 17 Database Connectivity Web Technologies
- 1. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Database Principles Fundamentals of Design, Implementation, and Management Carlos Coronel, Steven Morris, Keeley Crockett, Craig Blewett CHAPTER 17 DATABASE CONNECTIVITY AND WEB TECHNOLOGIES
- 2. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA In this chapter, you will learn: • About the different database connectivity technologies • What Extensible Markup Language (XML) is and why it is important for Web database development • About the functionality and features of various database connectivity technologies: ODBC, OLE, ADO.NET and JDBC • What services are provided by Web application servers • About cloud computing and how it enables the database-as-a- service model. • About the Semantic Web
- 3. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Database Connectivity • Refers to mechanisms through which application programs connect and communicate with data repositories • Databases store data in persistent storage structures so that they can be retrieved at a later time for processing • Database connectivity software works in a client/server architecture, in which processing tasks are split among multiple software layers
- 4. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA 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
- 5. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Native SQL Connectivity (continued)
- 6. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA ODBC, DAO,RDO and UDA • 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)
- 7. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA ODBC, DAO, and RDO (continued) • Data Access Objects (DAO) – Microsoft's API that allows access to the Microsoft Access database. – DAO was Microsoft's first object-oriented API. However, while DAO is still widely used there is a move towards ActiveX Data Objects (ADO).
- 8. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA ODBC, DAO, and RDO (continued) • Remote Data Objects (RDO) – was a higher level object-oriented application interface primarily used in Microsoft Visual Basic. – allowed developers to interface directly with ODBC data sources. • Microsoft's Universal Data Access (UDA) – a new framework – UDA is designed to bring about a single uniform API that will allow access to relational and non-relational databases.
- 9. ODBC, DAO, and RDO (continued)
- 10. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA ODBC, DAO, RDO and UDA (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
- 11. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA ODBC, DAO, RDO and UDA (continued)
- 12. ODBC, DAO, RDO and UDA (continued)
- 13. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA OLE-DB • Object Linking and Embedding for Database (OLE-DB) • Database middleware that adds object-oriented functionality for access to relational and non-relational data • Composed of series of COM objects that provide low-level database connectivity for applications • OLE-DB model is better understood when you divide its functionality into following types of objects: – Consumers – Providers
- 14. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA OLE-DB (continued)
- 15. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA OLE-DB (continued) • 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
- 17. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA 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
- 18. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA ADO.NET (continued)
- 19. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA 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
- 20. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Java Database Connectivity (JDBC) • Java Database Connectivity (JDBC) is an application programming interface that allows a Java program to interact with a wide range of data sources, including relational databases, tabular data sources, spreadsheets, and text files. • JDBC allows a Java program to establish a connection with a data source, prepare and send the SQL code to the database server, and process the result set.
- 21. Java Database Connectivity (JDBC) (Continued)
- 22. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA PHP • PHP or Hypertext Preprocessor, is a widely-used general-purpose scripting language that is especially • suited for web development and is seen as an alternative to Microsoft’s ASP. • A Server-Side Scripting Language, which means that it is interpreted on the web server before the webpage • is sent to a web browser to be displayed. • PHP supports connectivity to a number of different databases through specific database extensions in the case of MySql to connecting through ODBC extensions for ORACLE.
- 23. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Database Internet Connectivity • 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 – Allow anywhere, anytime data access using mobile smart devices via the internet. – give fast and effective information dissemination through universal access from across street or across globe
- 24. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Internet Databases (continued)
- 25. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA 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
- 26. Web-to-Database Middleware: Server- side Extensions (continued)
- 27. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Web Server Interfaces • Two well-defined Web server interfaces: – Common Gateway Interface (CGI) – Application programming interface (API)
- 28. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Web Server Interfaces (Continued)
- 29. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA The Web Browser • Software that lets users navigate (browse) Web • Located in client computer • End-user interface to World Wide Web • Interprets HTML code received from Web server • The Web is a stateless system – at any given time, a Web server does not know the status of any of the clients communicating with it.
- 30. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Client-Side Extensions • Client-side extensions add functionality to the Web browser. Although client-side extensions are available in various forms, the most commonly encountered extensions are: – Plug-ins. – Java and JavaScript. – ActiveX and VBScript.
- 31. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Web Application Servers • A Web application server is a middleware application that expands the functionality of Web servers by linking them to a wide range of services, such as databases, directory systems, and search engines. • The Web application server also provides a consistent run-time environment for Web applications.
- 32. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Web Application Servers (Continued) • Web application servers can be used to perform the following: – Connect to and query a database from a Web page. – Present database data in a Web page using various formats. – Create dynamic Web search pages. – Create Web pages to insert, update, and delete database data. – Enforce referential integrity in the application program logic. – Use simple and nested queries and programming logic to represent business rules.
- 33. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Web Application Servers (Continued) • Web application servers provide features such as: – An integrated development environment with session management and support for persistent application variables – Security and authentication of users through user IDs and passwords – Computational languages to represent and store business logic in the application server – Automatic generation of HTML pages integrated with Java, JavaScript, VBScript, ASP, and so on – Performance and fault-tolerant features – Database access with transaction management capabilities – Access to multiple services, such as file transfers (FTP), database connectivity, e-mail, and directory services
- 34. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Web Database Development • LAMP is made up of the Linux operating system, Apache web server, MySQL database and the PHP programming language (although Perl and Python can be used instead of PHP). • Often used within organisations which need an effective way of managing organisational data but do not have the time or money to invest in a large scale costly development web development projects. • LAMP allows web developers to build efficient web applications that are reliable and stable.
- 35. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Web Database Development (Continued)
- 36. Web Database Development (Continued)
- 37. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Extensible Markup Language (XML) • Extensible Markup Language (XML) is a metalanguage used to represent and manipulate data elements. • XML is designed to facilitate the exchange of structured documents, such as orders and invoices, over the Internet.
- 38. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Extensible Markup Language (XML)
- 39. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Document Type Definitions (DTD) and XML Schemas
- 40. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Document Type Definitions (DTD) and XML Schemas (continued)
- 41. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Document Type Definitions (DTD) and XML Schemas (continued)
- 42. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Document Type Definitions (DTD) and XML Schemas (continued)
- 43. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA XML Presentation
- 44. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA XML Presentation (continued)
- 46. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA XML Applications • B2B exchanges • Legacy systems integration • Web page development • Database support • Database metadictionaries • XML databases • XML services
- 47. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA SQL/XML and XQuery • SQL/XML and XQuery are two standard querying languages which are used to retrieve data from a relational database in the XML format. • SQL/XML is an extension of SQL that is part of ANSI/ • ISO SQL 2011 and is often referred to as being SQL-centric. This is because only small additions have been made to the standard SQL language.
- 48. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA SQL/XML and XQuery (continued) • The xmlelement() function can be incorporated into the SQL statement like this: SELECT XMLELEMENT(NAME ‘VENDOR’, XMLELEMENT(NAME ‘VEND_CODE’, V.VENDCODE), XMLELEMENT(NAME ‘VENDOR_NAME’, V.VEND_CONTACT), XMLELEMENT(NAME ‘VEND_AREACODE’, V.VEND_AREACODE)) FROM VENDOR V;
- 49. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA SQL/XML and XQuery (continued) • Each row returned by the query corresponds to one VENDOR element and which is represented as <VENDOR> <VEND_CODE>230</VEND_CODE> <VENDOR_NAME>Shelly K. Smithson</VENDOR_NAME> <VEND_AREACODE>7325</VEND_AREACODE> </VENDOR>
- 50. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA
- 51. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Cloud Computing Services • According to the National Institute of Standards and Technology (NIST), cloud computing is “a computing model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computer resources (e.g., networks, servers, storage, applications and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.” • The term cloud services is used in this book to refer to the services provided by cloud computing.
- 52. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Cloud Computing Services (continued)
- 53. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Cloud Computing Services (continued)
- 54. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Cloud Implementation Types • Public cloud. This type of cloud infrastructure is built by a third-party organisation to sell cloud services to the general public. • Private cloud. This type of internal cloud is built by an organisation for the sole purpose of servicing its own needs. • Community cloud. This type of cloud is built by and for a specific group of organisations that share a common trade, such as agencies of the federal government, the military, or higher education.
- 55. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA 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
- 56. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Types of Cloud Services • Software as a Service (SaaS). • Platform as a Service (PaaS). • Infrastructure as a Service (IaaS).
- 57. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Types of Cloud Services (Continued)
- 58. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Advantages and Disadvantages
- 59. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA SQL Data Services • SQL data services (SDS) refers to a cloud computing-based data management service that provides relational data storage, access, and management to companies of all sizes without the typically high costs of in-house hardware, software, infrastructure, and personnel.
- 60. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA SQL Data Services (Continued) • Benefits: – Hosted data management. – Standard protocols – A common programming interface
- 61. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA SQL Data Services (Continued) • SQL data services offer the following advantages when compared with in-house systems: – Highly reliable and scalable relational database for a fraction of the cost – High level of failure tolerance because data are normally distributed and replicated among multiple servers – Dynamic and automatic load balancing – Automated data backup and disaster recovery included with the service – Dynamic creation and allocation of database processes and storage
- 62. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA The Semantic Web • The Semantic Web was conceived by Tim Berners-Lee • In 2001, he published his initial vision of the future of the WWW as • “If the interaction between person and hypertext could be so intuitive that the machine-readable information space gave an accurate representation of the state of people's thoughts, interactions, and work patterns, then machine analysis could become a very powerful management tool, seeing patterns in our work and facilitating our working together through the typical problems which beset the management of large organisations.”1
- 63. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA The Semantic Web (continued) • Today, the semantic web is often referred to as a Web of data • Research and work on the sematic web is on-going and led by the W3C in collaboration with researchers and industry . 3 • The aim is to produce a framework which allows all data to be shared and reused across applications, without any boundaries. • The framework will establish common formats for integration and combination of data from different sources and develop a language for modelling how data relates to real world objects. • The framework is based upon the on the Resource Description Framework (RDF) which is a model that has a number of features for interchanging data over the WWW.
- 64. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Summary • Database connectivity refers to the mechanisms through which application programs connect and communicate with data repositories • Microsoft database connectivity interfaces are dominant players in the market and enjoy the support of most database vendors • Native database connectivity refers to the connection interface that is provided by the database vendor and is unique to that vendor
- 65. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Summary (continued) • Object Linking and Embedding for Database (OLE-DB) is a database middleware developed with the goal of adding object-oriented functionality for access to relational and non- relational data • Database access through the Web is achieved through database-to-middleware software • The Semantic Web, often referred to as a Web of data, is a framework that allows all data on the WWW to be shared and reused across applications, without any boundaries.
- 66. Database Principles 3rd Ed., Coronel, Morris, Crockett, Blewett ©2020 Cengage EMEA Summary (continued) • Extensible Markup Language (XML) facilitates the exchange of B2B and other data over the Internet • XML provides the semantics that facilitates the exchange, sharing, and manipulation of structured documents across organisational boundaries • Cloud computing is a computing model that provides ubiquitous, on-demand access to a shared pool of configurable resources that can be rapidly provisioned. SQL data services (SDS) refers to a cloud computing-based data management service that provides relational data storage, ubiquitous access, and local management to companies of all sizes. – This service enables rapid application development for businesses with limited information technology resources. SDS allows rapid deployment of business solutions using standard protocols and common programming interfaces.