MySQL has become one of the most popular databases for Web applications. The database is well suited for common Web-related tasks like content management, and for implementing Web features like discussion boards and guestbooks. For a time, some developers avoided MySQL for commercial applications because it did not implement certain features, such as transactions. But this is no longer the case, and MySQL is a great choice for just about any Web-based application.

In this article I’ll give you an overview of MySQL’s features and drawbacks, show you how to install MySQL on Mac OS X, and introduce you to some of MySQL’s notable technical aspects.

MySQL Features

Perhaps the most prominent feature of MySQL is its speed when running SQL SELECT statements. MySQL was built for speed. The core of the MySQL engine is very small and streamlined, and the default table type (a modified ISAM table) was designed specifically for running SELECTs quickly. If your application calls for the advantages of a relational structure but the database contents are relatively static — as is often the case with Web content — MySQL’s speed is a great advantage.

MySQL is also undeniably stable. In both your production and serving environments, you can be reasonably confident that MySQL will be up and processing queries as long as power flows to your machine.

Another important benefit is that MySQL is relatively easy to learn. Even if you’re new to relational databases, you can learn MySQL and create very sophisticated Web applications in a short period of time.

The popularity of MySQL is a benefit as well, because if you run into difficulty, you can lean on the active community that supports MySQL. There are many mailing lists dedicated to MySQL, and most questions find quick and thorough answers.

MySQL Drawbacks

If you are an advanced database user, you should be aware of some of MySQL’s limitations. MySQL’s implementation of standard query language is missing support for sub-selects, foreign key constraints (for some table types), stored procedures, and views. If you feel you need these features, you’re probably better off looking into PostgreSQL, FrontBase, or another database.

Lack of support for transactions used to be a drawback of MySQL, but this has been addressed. Now, on Mac OS X, you can use the MySQL InnoDB table type and have access to row-level locking and robust transaction support, as well as foreign key constraints.

Installing MySQL

If you’re running Mac OS X Server, you are in luck — MySQL is already there. Just go to Applications/Server/MySQL Manager to access it. If you are running Mac OS X Client, you’ll have to install MySQL. if you have already installed a version of MySQl and want to upgrade, I can recommend the upgrade instructions from http://www.entropy.ch. For a new installation, follow the Mac OS X installation instructions for the MySQL provided binary distribution ( a true Mac OS X installer package file) at http://dev.mysql.com/doc/refman/5.0/en/mac-os-x-installation.html and be done with it. However, sometimes you want to compile and install directly from the source, either because you are changing the default build settings, or you want the latest and greatest version before there’s a binary installer. The following will help you through that process.

When installing MySQL, you need to be aware of the potential effect this will have on the security of your system, as a database server can open an avenue of attack. In the example below, I show how to install MySQL on Mac OS X while maintaining the security of your system.

One basic security tenet is that of “least privilege.” In short, this means that everyone and everything should have only the privileges required for it to complete its task(s). Those privileges should be available for the least amount of time possible—ideally, once the task is completed, the privileges should be revoked.

I’m also choosing to build MySQL from source, rather than install a pre-built binary. This gives greater control over the installation, as you’ll see below.

Configuring and Compiling MySQL

I plan to install mysql in /usr/local/mysql. I also plan to locate the mysql UNIX socket under the /usr/local/mysql/ directory as /usr/local/mysql/run/mysql_socket so that it will be publicly available, but associated with the MySQL installation. Note that in a standard installation, the socket file would be placed in /tmp.

You can now download the source via a Web browser.

Once you have the source, you can pretty much follow the quick install directions from the mysql documentation pages, adding only debug support ( — with-debug) and the build environment comment ( — with-comment). The configure command should look like:

./configure --prefix=/usr/local/mysql
--with-unix-socket-path=/usr/local/mysql/run/mysql_socket
--with-mysqld-user=mysql --with-comment --with-debug

Once the configuration completes, running make, and then sudo make install, installs mysql in /usr/local/mysql. Running sudo /usr/local/mysql/bin/mysql_install_db --force adds the var/ space for databases and creates the default databases (mysql and test). You also need to add the run/ directory where the mysql UNIX socket will live, with sudo mkdir /usr/local/mysql/run. Once all of that is done, a directory listing should look like:

% ls -Fla /usr/local/mysql/
total 26
drwxr-xr-x 13 root wheel 1024 Jun 5 13:42 ./
drwxr-xr-x 11 root wheel 1024 Jun 5 12:19 ../
drwxr-xr-x  2 root wheel 1024 Jun 5 12:20 bin/
drwxr-xr-x  3 root wheel 1024 Jun 5 12:19 include/
drwxr-xr-x  2 root wheel 1024 Jun 5 12:19 info/
drwxr-xr-x  3 root wheel 1024 Jun 5 12:19 lib/
drwxr-xr-x  2 root wheel 1024 Jun 5 12:20 libexec/
drwxr-xr-x  3 root wheel 1024 Jun 5 12:20 man/
drwxr-xr-x  6 root wheel 1024 Jun 5 12:21 mysql-test/
drwxr-xr-x  2 root wheel 1024 Jun 5 13:42 run/
drwxr-xr-x  3 root wheel 1024 Jun 5 12:20 share/
drwxr-xr-x  7 root wheel 1024 Jun 5 12:21 sql-bench/
drwx------  4 root wheel 1024 Jun 5 13:37 var/

Note that at this point everything is owned by root — meaning the mysql account won’t be able to write to the databases under var/ nor be able to create the mysql UNIX socket in the run/ directory. Since we want to run the MySQL database under the mysql account, and not under the root account, we need to change the group association of /usr/local/mysql to the group mysql, and the ownership of /usr/local/mysql/run and /usr/local/mysql/var to the mysql account, as follows:

sudo chgrp -R mysql /usr/local/mysql
sudo chown -R mysql /usr/local/mysql/run /usr/local/mysql/var

The directory listing now looks like:

% ls -Fla /usr/local/mysql
total 26
drwxr-xr-x 13 root  mysql 1024 Jun 5 13:42 ./
drwxr-xr-x 11 root  wheel 1024 Jun 5 12:19 ../
drwxr-xr-x  2 root  mysql 1024 Jun 5 12:20 bin/
drwxr-xr-x  3 root  mysql 1024 Jun 5 12:19 include/
drwxr-xr-x  2 root  mysql 1024 Jun 5 12:19 info/
drwxr-xr-x  3 root  mysql 1024 Jun 5 12:19 lib/
drwxr-xr-x  2 root  mysql 1024 Jun 5 12:20 libexec/
drwxr-xr-x  3 root  mysql 1024 Jun 5 12:20 man/
drwxr-xr-x  6 root  mysql 1024 Jun 5 12:21 mysql-test/
drwxr-xr-x  2 mysql mysql 1024 Jun 5 13:42 run/
drwxr-xr-x  3 root  mysql 1024 Jun 5 12:20 share/
drwxr-xr-x  7 root  mysql 1024 Jun 5 12:21 sql-bench/
drwx------  4 mysql mysql 1024 Jun 5 13:37 var/

You can now start mysql and perform a few important tasks, like setting a mysql password to protect the database itself. Note that, while starting the database requires system root privileges, actions within the database itself do not require system root privileges, but database root privileges. It is somewhat confusing that MySQL uses the account name “root” for its all-powerful account, just as the system does, even though they are completely separate entities.

Starting mysql is accomplished with:

sudo /usr/local/mysql/bin/mysqld_safe --user=mysql &

Now you can run through some of the basic tests — but first, go ahead and secure the database by adding a password for the database “root” user, as follows:

/usr/local/mysql/bin/mysqladmin -u root password sniggle

Here “sniggle” is the password you are assigning to the database root account. In MySQL, a single user is associated with a username and a host. Most often on your development machine you will be connecting to the database locally, so the host will be “localhost”. However, if you are attempting to connect from a different machine, you will have to assign permissions based on both username and hostname. For more information on users and passwords within MySQL, read about MySQL’s grant tables, and the grant and revoke statements.

Conclusion

MySQL is a great database for Web applications and a great complement to a Mac OS X development environment. Install it on your machine and create applications in Perl, PHP, JSP, or whatever languages you like best. To administer a MySQL installation on Mac OS X, you can look to popular tools such as the Web-based phpMyAdmin from phpwizard.net, or MacSQL from Runtime Labs.

For information about starting MySQL on startup, see this article from macosxfaq.com.

WebObjects gives you the ability to build or use web services without writing low-level SOAP, XML or WSDL documents. The WebObjects tools enable code-free generation, configuration and testing of web services from existing data assets. Because these web services can interoperate with clients written in many languages, including Java, AppleScript, and Perl, you can quickly create integrated solutions that would otherwise require a lot of coding.

This article shows you how to take an existing database and publish assets as web services, including a service description, all without writing any code.

Installation

If you don’t own your own copy of WebObjects 5.2, it is
available in a free trial version for Mac OS X version 10.2
or later at Apple
Developer Connection. Directions on how to find the
download are on the
href=”http://www.apple.com/webobjects/getting_started.html”>

WebObjects – Getting Started page. We will be working
with Mac OS X 10.3 and Xcode so you will also need the Xcode
Tools for Mac OS X, available for download at the Apple
Developer Connection web site, in the Developer Tools
section. After you download everything, install the
WebObjects_X_Developer package in the Developer
folder and restart your system. You must upgrade to
WebObjects 5.2.2 via Software Update or you can get the
manual update at the page
href=”http://docs.info.apple.com/article.html?artnum=107649″
>About the WebObjects 5.2.2 Update.

If you don’t want to build the project by hand and just want to run it, you can download the example used in this article.

The Data Model

Installing WebObjects installs a sample database in addition to the WebObjects tools. Navigate to /Library/Frameworks/JavaRealEstate.framework/Resources/ and open the RealEstate.eomodeld file. This launches EOModeler and opens the model file of a ficticious real estate database of houses in Silicon Valley. EOModeler is used to reverse-engineer databases, automatically finding all tables, columns and relationships. At runtime the WebObjects persistence engine automatically maps and generates Java objects from JDBC databases. You don’t need to write any SQL code.

The image below shows the tables found in the real estate database on the left; however, EOModeler refers to them as entities. We’re going to work with two of them, Listing and ListingAddress. On the right are the attributes (columns) of a Listing. You may quit EOModeler. We don’t need it anymore.

Building the Server Application

The model can now be used to automatically generate a web services-enabled server application. First, launch Xcode, located in /Developer/Applications. Choose File > New Project. In the New Project Assistant, select Direct to Web Services Application. Name the project Houses. Accept the defaults until you see the Choose EOModels pane. Add the RealEstate.eomodeld model file at /Library/Frameworks/JavaRealEstate.framework/Resources. In the Build and Launch Project pane, deselect “Build and launch project now” and click Finish.

In the Xcode main window, click the triangle next to Resources. Select the Properties file and edit it so it looks like this:

WOAutoOpenInBrowser=false

WOPort=55555

Click the Build and Run button in the Xcode toolbar to build and run the application. When you see the message Waiting for requests..., the WebObjects server application is running.

Everything should look like the image below:

Configuring the Web Service

To customize a Direct to Web Services application you use the Web Services Assistant. It’s located in /Developer/Applications.

After you launch the Assistant, the Connect dialog appears. Enter http://localhost:55555 in the text input field and click Connect.

Most web services define a service with one or more operations, or methods. We’ll build a service HouseSearch and define an operation searchByPrice, which finds all house listings under a certain price. In addition to searching, WebObjects can generate Web service operations that let you insert, delete or update entries in a database.

In the Web Services Assistant main window, select http://localhost:55555 in the left-hand side list. Click the New Service toolbar button. Enter HouseSearch in the Service Name text field. Select Listing in the Available list of the Public Entities pane and add it by clicking the left-pointing arrow. Repeat for ListingAddress, making sure that the Enabled option is selected.

Now you add an operation to the HouseSearch Web service and define the calling arguments:

Click New Operation in the toolbar.

Enter searchByPrice in the Name text field.

Choose Listing from the Entity pop-up menu. Make sure the Type is search. Click OK.

In the main window, select askingPrice in the Available list in the Arguments pane and click the left-arrow button.

Choose “<=” from the Operator pop-up menu.

Select Return SOAP Struct.

Everything should look like the image below:

Now, define the return values for this operation:

In the Return Values pane, select askingPrice from the Available list and click the left-arrow button.

Click the triangle next to address. Select address.street and click the left-arrow button. Repeat for address.city, address.state and address.zip.

Click the Save toolbar button.

You have now defined the HouseSearch service with the searchByPrice operation that finds all houses with an asking price less than or equal to its askingPrice argument and returns an array of listings, each with their asking price and address.

Everything should look like the image below:

Testing the Service

Select searchByPrice under HouseSearch under http://localhost:55555.

Click the Test toolbar button. A test window is automatically generated with the appropriate user interface to test the searchByPrice operation.

Enter 250000 in the text input field and click Test. An empty list is returned. That is because a quarter of a million dollars won’t buy a home in Silicon Valley. Try again, entering 300000. This time three entries should be returned with their asking price and address.

See the image below:

Generating WSDL Documents

Web Services Definition Language or WSDL is an XML format for describing web services and the operations they provide.

In the test window, click the WSDL tab. The WSDL document describing the HouseSearch Web service and its searchByPrice operation appears.

The WSDL document can also be retrieved directly from the server via the URL http://localhost:55555/cgi-bin/WebObjects/Houses.woa/ws/HouseSearch?wsdl. If you want to download the WSDL document and look at it, using the curl command is a convenient way to do so. In Terminal, execute the following command:

curl 'http://localhost:55555/cgi-bin/WebObjects/Houses.woa/ws/HouseSearch?wsdl' -o mywsdl.txt

Conclusion

You have developed, configured and tested a working Web
service with WebObjects without writing any SOAP, XML or
Java code. In addition, you learned how to obtain the WSDL
description that you can publish so client applications can
be built that use the service.

For more information about web services and WebObjects,
please refer to the manual titled “Web Services”
on the WebObjects Documentation site.

Editor’s note: WebObjects can do a lot more than web
services, including dynamic Web pages and distributed Java
Client applications. To find out more about WebObjects,
visit the
href=”http://www.apple.com/WebObjects/”>Web Objects page.

You don’t need to be an experienced webmaster to host your own home page, website, or Web 2.0 application with Mac OS X Server. With its intuitive administrative interface, you can immediately start up a static website or deploy even the most sophisticated of sites.

Powered by Apache.

Included in Mac OS X Server is Apache, the most widely used HTTP server on the Internet. Apache is preconfigured with default settings, so deployment is as simple as starting the Web service. Any HTML content saved to the server’s default web folder will be served over the Internet automatically. Mac OS X Server offers experienced webmasters support for using either Apache 2.2 or Apache 1.3 from within the Server Admin application.

Deploy the Web 2.0.

Everything you need to develop, deploy, and host reliable Web 2.0 applications is included. Mac OS X Server ships with a full complement of server applications and frameworks including Apache 2, Ruby on Rails, Tomcat 5, and WebObjects 5.4. For hosting enterprise-class applications, Mac OS X Server includes a 64-bit Java VM optimized for the latest generation of Intel multicore processors.

Hosting multiple websites.

Support for virtual hosting in Mac OS X Server allows you host multiple websites on a single server. Using Server Admin, you can configure each website on your server to have a different domain name (using virtual domains) and even a different IP address. In addition, each website can be configured with unique security options and separate log files for tracking and reporting.

Apache Performance

Up to 50% improvement over Tiger Server^*

Leopard Server Xserve Quad Xeon

1.56x

Tiger Server Xserve Quad Xeon

Baseline

Apache performance

Be dynamic.

Apache is extremely flexible, so you can add dynamic content for a more interactive Internet solution. Dynamic content enables you to host stores, auctions, shared calendars, portal systems, polls, and other database-driven services. The robust server-side architecture in Apache supports dynamic content generated by server-side includes (SSIs), PHP, Perl, Apache modules, and custom CGIs — as well as by JavaServer Pages (JSPs) and Java Servlets.

Secure web services.

Mac OS X Server integrates OpenSSL with the Apache web server, providing support for strong 128-bit encryption and public key infrastructure (PKI) authentication using X.509 digital certificates. This high-grade security architecture protects credit card information and other confidential personal and business data transmitted during web transactions.