pub fn trigger_for(
child: &TableInfo,
parent: &TableInfo,
key: &ForeignKeyInfo,
event: ForeignKeyEvent,
database: &[u8],
deferred: bool,
limits: &Limits,
) -> Option<TriggerInfo>Expand description
Builds the trigger that enforces one key for one event, if there is one.
None means the event needs no trigger - a NO ACTION parent key whose
checks are deferred to the commit, for instance, or a child key whose
columns this update does not touch.