Apple - Where is the Launchpad database stored and is there a way to edit it directly?
The Launchpad database is located at ~/Library/Application Support/Dock/*some-hex-name*.db
To edit it, you'll have to use SQLite. You can do this on the command line, or with a graphic interface.
See this Ask Different question for recommendations for a GUI app.
MacOS Sierra and newer
On macOS Sierra and newer the old launchpad database does not exists anymore. Instead every user has his personal launchpad database somewhere inside /private/var/folders (contains a lot of cryptic names).
How to find the database
The personal database is owned by you user, so you can use the following command to find out the path of the database:
echo $(find /private/var/folders -user $(id -u) -name com.apple.dock.launchpad 2> /dev/null)/db/db
After you have the path to the new database, you can continue to edit it like before (e.g. using sqlite3 command).
Thanks to Chris Perry from Jamf Nation for sharing what he found! See his post here.
Apologies for tacking this on to a 2-year old thread, but FWIW the value for some-hex-name is stored in ~/Library/Preferences/ByHost/com.apple.dock.*another-hex-name*.plist as LaunchPadDBName.
It seems like the number itself is not important, and may in fact be random; but, it may probably needs to conform to the UUID format. Changing this value for a user, then logging in, will result in a new .db being created if it does not already exist.
You can use this to set multiple accounts to use a pre-defined LaunchPad configuration, etc.
"another-hex-name" is the UUID of the computer
A simpler way to access this value is to use:
defaults -currentHost read com.apple.dock LaunchPadDBName
This makes use of the -currentHost argument of the defaults command:
Host Optionally you can restrict changes to a specific host
by default changes will apply to any host.
[-host hostname] Restrict to a remote machine.
[-currentHost] Restrict to the host the user is currently logged into.