Persist: add cascade rules to foreign keys

It turns out persist does support these, they're just not mentioned in
the yesod book.

(for future reference, the syntax is defined in Database.Persist.Quasi,
which does include some documentation [1])

[1] https://hackage.haskell.org/package/persistent-2.14.6.1/docs/Database-Persist-Quasi.html

1 files changed, 7 insertions, 9 deletions

diff --git a/lib/Persist.hs b/lib/Persist.hs
index f722487..637155a 100644
--- a/lib/Persist.hs
+++ b/lib/Persist.hs
@@ -103,7 +103,7 @@ Import sql=tt_imports
   date UTCTime
 
 Stop sql=tt_stop
-  ticket TicketId
+  ticket TicketId OnDeleteCascade OnUpdateCascade
   station StationId
   arrival GTFS.Time
   departure GTFS.Time
@@ -131,25 +131,23 @@ Tracker sql=tt_tracker_token
   deriving Eq Show Generic
 
 TrackerTicket
-  ticket TicketId
-  tracker TrackerId
+  ticket TicketId OnDeleteCascade OnUpdateCascade
+  tracker TrackerId OnDeleteCascade OnUpdateCascade
   UniqueTrackerTicket ticket tracker
 
-
 -- raw frames as received from OBUs
 TrainPing json sql=tt_trip_ping
-  -- ticket TicketId
-  token TrackerId
+  ticket TicketId OnDeleteCascade OnUpdateCascade
+  token TrackerId OnDeleteSetNull OnUpdateCascade
   geopos Geopos
   timestamp UTCTime
   sequence Double
-  ticket TicketId
   deriving Show Generic Eq
 
 -- status of a train somewhen in time (may be in the future),
 -- inferred from trainpings / entered via controlRoom
 TrainAnchor json sql=tt_trip_anchor
-  ticket TicketId
+  ticket TicketId OnDeleteCascade OnUpdateCascade
   created UTCTime
   when GTFS.Seconds
   sequence Double
@@ -160,7 +158,7 @@ TrainAnchor json sql=tt_trip_anchor
 -- TODO: multi-language support?
 Announcement json sql=tt_announcements
   Id UUID default=uuid_generate_v4()
-  ticket TicketId
+  ticket TicketId OnDeleteCascade OnUpdateCascade
   header Text
   message Text
   url Text Maybe