Fix unique constraint error

CHANGELOG.md

@@ -3,3 +3,13 @@
 - Update to be compatible with networkx 2.0.  There should be no
   changes needed with networkx 1.11 (it should still work), but bugs
   are possible.  Please report.  Github #34
+
+- Allow one to incrementally update databases with new GTFS files:
+  `INSERT OR REPLACE` into existing databases (and don't create
+  indexes if they already exist).  It is possible that there are
+  subtle bugs here - check carefully and report back.  #27, thanks to
+  @evelyn9191 for the change.
+
+
+
+

gtfspy/import_loaders/stop_times_loader.py

@@ -57,7 +57,7 @@ def index(cls, cur):
         # This is used for the stop frequencies analysis.
         #cur.execute('CREATE INDEX idx_stop_times_tid_ath_sid ON stop_times (trip_I, arr_time_hour, stop_id)')
             # ^-- much slower than the next index.
-        cur.execute('CREATE INDEX idx_stop_times_ath_tid_sid ON stop_times (arr_time_hour, trip_I, stop_I)')
+        cur.execute('CREATE INDEX IF NOT EXISTS idx_stop_times_ath_tid_sid ON stop_times (arr_time_hour, trip_I, stop_I)')
 
     # This has now been moved to DayTripsMaterializer, but is left
     # here in case we someday want to make DayTripsMaterializer

gtfspy/import_loaders/table_loader.py

@@ -279,7 +279,7 @@ def insert_data(self, conn):
                 # proceed.  Since there is nothing to import, just continue the loop
                 print("Not importing %s into %s for %s" % (self.fname, self.table, prefix))
                 continue
-            stmt = '''INSERT INTO %s (%s) VALUES (%s)''' % (
+            stmt = '''INSERT OR REPLACE INTO %s (%s) VALUES (%s)''' % (
                 self.table,
                 (', '.join([x for x in fields if x[0] != '_'] + self.extra_keys)),
                 (', '.join([":" + x for x in fields if x[0] != '_'] + self.extra_values))