An SQL statement to delete a subscription. Special formatting
characters may be used. Special variable %2 contains a tenant id, %3
contains object's id and %4 contains object's name. If
DeleteSubscriptionQuery is defined as an empty string, then the query will
not be executed.
%0 and %1 are
undefined.
DeleteSubscriptionQuery
defaults
to:
DELETE FROM SUBSCRIPTIONS WHERE tenant_id=%2 AND id=%3