Web Server Administration

Web Server Administration Chapter 7 Installing and Testing a Programming Environment

Overview • Understand the need for programming languages • Understand database management systems (DBMSs) • Install and test DBMSs • Understand the Web-based programming environment • Program with databases

The Need for Programming Languages • Web pages with just HTML statements are static pages • Pages that contain programming statements allow changes and they are called dynamic pages • Programming languages can also be used to update databases and communicate with other systems

Database Management Systems (DBMSs) • The purpose of a DBMS is to store data in an organized manner for further processing • Structured Query Language (SQL) is the language used to define and manipulate the data • Most databases are relational and organize data into tables

Database Tables • A primary key uniquely defines a row of data • SSN in the Employee table and Department number in the Department table • A foreign key is a column in a table that is related to a primary key • Department number in the Employee table

Three Categories of SQL • Data Manipulation Language (DML) • Used for programming and to insert, update, delete, and retrieve data • Data Definition Language (DDL) • Used to create tables and other related structures in a database • Data Control Language (DCL) • Allows you to control access to tables

Installing and Testing SQL Server • As with other applications, a wizard guides you through the installation • By default, it uses the user name you logged on as (typically administrator) to gain access to the system • This should be changed to "Use the Local System account" for single server systems • If SQL Server needs to communicate with other servers, create a special domain account

Installing and Testing SQL Server-Authentication Mode • The Windows Authentication Mode controls access to the database based on Windows users • The Mixed Mode allows for SQL Server Authentication • This is more appropriate for Web-based systems • The sa (systems administrator) account is a SQL Server user that has complete control over the databases

Installing and Testing SQL Server-Creating Tables • The GUI interface is similar to Access in creating a table

Installing and Testing SQL Server-Filling Tables with Data • Although SQL statements are often used to manipulate data, you can use something similar to a spreadsheet

Installing and Testing MySQL for Red Hat Linux • As with other applications, you run an RPM file • Start MySQL with /etc/rc.d/init.d/mysqld start • The command-line interface is accessed withmysql • Create a password for mysql root account withSET PASSWORD FOR root=PASSWORD('password');

Login to mysql and Create a Database • To login from the shell prompt use mysql –uroot –ppassword • To create a database called hrcreate database hr; • In order to do any operations on the database such as create tables, you have to "use" ituse hr;

Create Tables and Insert Data • The following script creates the employee table and adds three employees create table employee ( ssn char(9) primary key, firstname varchar(20), lastname varchar(30), deptno char(2), salary numeric(6)); insert into employee values('553879098','Lynn','Gweeny',10,55000); insert into employee values('623827368','Elark','Kaboom',10,60000); insert into employee values('756838998','John','Doh',20,45000);

Web-based Programming Environment • Cookie • Text that a Web site stores on your disk • Common Gateway Interface (CGI) • A protocol that allows the operating system to interact with the Web server • Practical extraction and reporting language (Perl) • First popular language for Web servers • Java Server Pages (JSP) • Language similar to Java

Web-based Programming Environment • Active Server Pages (ASP) • Script-based environment available on all IIS Web servers • ASP.NET • Compiled programs operate under .NET Framework • .NET Framework is an integral part of Windows Server 2003 and can be installed on Windows 2000 • PHP Hypertext Protocol (PHP) • Popular language available on most platforms • The structure of JSP, ASP, and PHP are similar

Using Forms • The following HTML produces a form • When the submit button is pressed, the data in the form is sent to the file designated as filename

Using ASP to Process a Form • The following file displays the information from the form • Notice how the items such as "first" match the text names on the form • ASP uses <% and %> for opening and closing tags • <%=request()%> is one way to retrieve data from the form

ASP.NET • ASP.NET is one of the many languages available under the .NET Framework that can be used for the Web • The programming model of ASP.NET is superior to that of ASP • Has modules for data validation that differentiates between browsers • Producing sophisticated reports is much easier

ASP.NET Program that Combines Form and Output

Shell Script in Linux • Uses CGI • First line states that the shell is being used • Not common because of lack of security

Perl Script to Display Contents of a Form • Notice how $cgi->param("first") is similar to ASP’s request("first")

Programming with Databases • Microsoft uses two methods to bridge the gap between programming languages and databases • Open Database Connectivity (ODBC) • The original standard • Object Linking and Embedding Database (OLEDB) • Current standard which is faster and more flexible • Linux often uses Java Database Connectivity (JDBC) • You can also have a direct connection between the language (such as PHP) and the database (such as MySQL)

Producing a Report • Connect to the database • Execute a SQL select statement to retrieve data from a table • Put the data in a recordset • Also known as a resultset, depending on the environment • Loop through the recordset and display the contents

A Report in ASP

Using Data Source Names (DSNs) • DNSs are connections to databases that an administrator creates on the server • They encapsulate the information on the previous slide concerning the connection information • The Data Sources (ODBC) wizard is in the Control Panel • Once it is created, you can create a connection withConn.open "DSN=humanresources;uid=sa"

Programming with ASP.NET • Although there is a connection and you send it a SQL select statement, the DataGrid component creates the report

Programming with PHP • Note the similarity between ASP and PHP, and how different they are from ASP.NET

Summary • Programming languages process data, allow you to create dynamic Web pages, and can produce other features • Database management systems organize data for processing

Web Server Administration