This is for software built from source according to:
http://hivelogic.com/articles/installing-mysql-on-mac-os-x/

Start MySQL

sudo launchctl unload -w /Library/LaunchDaemons/com.mysql.mysqld.plist

Stop MySQL

sudo launchctl load -w /Library/LaunchDaemons/com.mysql.mysqld.plist

There is currently an issue resulting from the fact that Apache on Mac OS X 10.5 is built as a 64 bit application. On Macs that support 64 bits (all current Mac models), Apache will run in 64 bit mode. This is incompatible with most ODBC drivers, including those currently available from Actual Technologies.
Until we can make 64 bit versions of our drivers available, we recommend a workaround to force Apache to run in 32 bit mode. Using the Terminal prompt, enter the following commands (this is for ppc machines, for intel switch ppc7400 to i386):

sudo mv /usr/sbin/httpd /usr/sbin/httpd.ub

sudo lipo -thin ppc7400 /usr/sbin/httpd.ub -output /usr/sbin/httpd.ppc7400

sudo ln -s /usr/sbin/httpd.ppc7400 /usr/sbin/httpd 

Now restart Web Sharing in the System Preferences, and continue with the instructions for "Invoking ODBC Functions from ODBC" below.
NOTE: if you ever need to restore Apache to 64 bit mode, just enter the following command:

sudo mv /usr/sbin/httpd.ub /usr/sbin/httpd

#starting SQL:

sudo /usr/local/mysql/support-files/mysql.server start

Stoping SQL:

sudo /usr/local/mysql/support-files/mysql.server stop

This script solves the excessive re-spawning problem that surfaces with Tiger-era launchd scripts. Tested using Lighttpd 1.4.18 and OS X 10.5.1.

Obviously, you may need to point to /usr/local/bin/lighttpd-start if you installed with --prefix=/usr/local

Put this at: /Library/LaunchDaemons/net.lighttpd.plist

<?xml version="1.0" encoding="UTF-8"?>
DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
        <key>Labelkey>
        net.lighttpd</string>
        <key>ProgramArgumentskey>
        
            /usr/bin/lighttpd-startstring>
        </array>
    <key>RunAtLoadkey>
    />
dict>
</plist>