It seems that the once super-simple MySQL on OS X install is no more in Leopard, that is until the MySQL developer community catches up. Now there is a small amount of terminal-fu that must be done to enable a mysql server on OS X, which has been covered in some other blog posts. But I will repeat the procedure here, since I added a script or two to make things a tiny bit simpler for me.
First, if you did a clean install of Leopard, then you need to download and install the MySQL server for OS X from the mysql.com. Just install the main server, not the preferences pane or the start up item.
Next download this launchd file and copy it to "/Library/LaunchDaemons/com.mysql.mysqld.plist"
Next change the ownership to root. Might as well set proper permissions while you are at it:
sudo chown root:wheel /Library/LaunchDaemons/com.mysql.mysqld.plist
sudo chmod 644 /Library/LaunchDaemons/com.mysql.mysqld.plist
Next load the file into launchd using launchctl
sudo launchctl load /Library/LaunchDaemons/com.mysql.mysqld.plistFinally, you can create some shell script to load and unload the server at will and place it where you normally place your binaries (mine is ~/bin/sqlserverctl ):
#!/bin/sh
case "$1" in
start)
sudo launchctl load -w /Library/LaunchDaemons/com.mysql.mysqld.plist
;;
stop)
sudo launchctl unload -w /Library/LaunchDaemons/com.mysql.mysqld.plist
;;
*)
echo "USAGE: $0 {start|stop}"
;;
esacUPDATE: There was a small error in my start script, namely and extra space in the case statement, it has been modified and fixed above.
UPDATE: If you install MySQL via MacPorts, then use the "+server" varient and use this launchd file instead
/Library/LaunchDaemons/org.macports.mysql5.plist 
