sqlite3_vtab_on_conflict —
Determine The Virtual Table Conflict Policy
int
sqlite3_vtab_on_conflict(sqlite3
  *);
This function may only be called from within a call to the xUpdate method of a
  virtual table implementation for an INSERT or UPDATE operation. The value
  returned is one of SQLITE_ROLLBACK, SQLITE_IGNORE, SQLITE_FAIL, SQLITE_ABORT,
  or SQLITE_REPLACE, according to the ON CONFLICT mode of the SQL statement that
  triggered the call to the xUpdate method of the virtual table.