This function or event no longer exists in version 6.0.2 (19034) of World of Warcraft. Please check the main API page for an up-to-date listing of the valid API functions
Queries the server for the player's completed quest information. This function is throttled by the server and can currently only be called every 15 minutes. This function will return immediately, and the QUEST_QUERY_COMPLETE will fire when the information is available from the server. At that point, it can be obtained using the GetQuestsCompleted function.
See also Quest functions.
Signature:
QueryQuestsCompleted()
This function must query the remote server, and any results will not be immediately available to the game client. Please see the function's documentation for more information about how to retrieve any results.