Regen VersionGroupPokemonMoveMethods when loading the database

Instead of relying on people to remember to run a script to regenerate
it, just do it automatically at load time. Only takes a couple seconds.
And hey, this gives us a free test too! (CI will complain if load+dump
isn't clean.)

Fixes #334
Fixes #74

pokedex/db/load.py

@@ -11,11 +11,15 @@ import sqlalchemy.sql.util
 import sqlalchemy.types
 
 import pokedex
+import pokedex.db.tables as t
 from pokedex.db import metadata, translations
 from pokedex.defaults import get_default_csv_dir
 from pokedex.db.dependencies import find_dependent_tables
 from pokedex.db.oracle import rewrite_long_table_names
 
+from sqlalchemy import and_
+from sqlalchemy.sql import exists
+
 
 def _get_table_names(metadata, patterns):
     """Returns a list of table names from the given metadata.  If `patterns`
@@ -370,6 +374,23 @@ def load(session, tables=[], directory=None, drop_tables=False, verbose=False, s
         session.commit()
         print_done()
 
+    VGPMM = t.VersionGroupPokemonMoveMethod
+    if VGPMM.__tablename__ in table_names or t.PokemonMove.__tablename__ in table_names:
+        print_start('Regenerating %s' % VGPMM.__tablename__)
+
+        session.query(VGPMM).delete()
+
+        q = session.query(t.VersionGroup.id, t.PokemonMoveMethod.id)
+        q = q.filter(exists().where(and_(
+                t.PokemonMove.pokemon_move_method_id == t.PokemonMoveMethod.id,
+                t.PokemonMove.version_group_id == t.VersionGroup.id)))
+        for version_group_id, pokemon_move_method_id in q:
+            session.add(VGPMM(
+                    version_group_id=version_group_id,
+                    pokemon_move_method_id=pokemon_move_method_id,
+            ))
+        session.commit()
+        print_done()
 
     print_start('Translations')
     transl = translations.Translations(csv_directory=directory)