1 files changed, 19 insertions, 0 deletions
diff --git a/src/fkey.c b/src/fkey.c
index 13b08dfe1..6ee35bf32 100644
--- a/src/fkey.c
+++ b/src/fkey.c
@@ -703,6 +703,25 @@ static void fkTriggerDelete(sqlite3 *dbMem, Trigger *p){
 }
 
 /*
+** Clear the apTrigger[] cache of CASCADE triggers for all foreign keys
+** in a particular database.  This needs to happen when the schema
+** changes.
+*/
+void sqlite3FkClearTriggerCache(sqlite3 *db, int iDb){
+  HashElem *k;
+  Hash *pHash = &db->aDb[iDb].pSchema->tblHash;
+  for(k=sqliteHashFirst(pHash); k; k=sqliteHashNext(k)){
+    Table *pTab = sqliteHashData(k);
+    FKey *pFKey;
+    if( !IsOrdinaryTable(pTab) ) continue;
+    for(pFKey=pTab->u.tab.pFKey; pFKey; pFKey=pFKey->pNextFrom){
+      fkTriggerDelete(db, pFKey->apTrigger[0]); pFKey->apTrigger[0] = 0;
+      fkTriggerDelete(db, pFKey->apTrigger[1]); pFKey->apTrigger[1] = 0;
+    }
+  }
+}
+
+/*
 ** This function is called to generate code that runs when table pTab is
 ** being dropped from the database. The SrcList passed as the second argument
 ** to this function contains a single entry guaranteed to resolve to