Migrate the database schema to SQLAlchemy

The new schema was generated with sqlacodegen and then manually adjusted
to fit schema/aur-schema.sql faithfully, both in the organisation of the
code and in the SQL generated by SQLAlchemy.

Initializing the database now requires the new tool aurweb.initdb.
References to aur-schema.sql have been updated and the old schema
dropped.

Signed-off-by: Lukas Fleischer <lfleischer@archlinux.org>

aurweb/initdb.py

@@ -0,0 +1,47 @@
+import aurweb.db
+import aurweb.schema
+
+import argparse
+import sqlalchemy
+
+
+def feed_initial_data(conn):
+    conn.execute(aurweb.schema.AccountTypes.insert(), [
+        {'ID': 1, 'AccountType': 'User'},
+        {'ID': 2, 'AccountType': 'Trusted User'},
+        {'ID': 3, 'AccountType': 'Developer'},
+        {'ID': 4, 'AccountType': 'Trusted User & Developer'},
+    ])
+    conn.execute(aurweb.schema.DependencyTypes.insert(), [
+        {'ID': 1, 'Name': 'depends'},
+        {'ID': 2, 'Name': 'makedepends'},
+        {'ID': 3, 'Name': 'checkdepends'},
+        {'ID': 4, 'Name': 'optdepends'},
+    ])
+    conn.execute(aurweb.schema.RelationTypes.insert(), [
+        {'ID': 1, 'Name': 'conflicts'},
+        {'ID': 2, 'Name': 'provides'},
+        {'ID': 3, 'Name': 'replaces'},
+    ])
+    conn.execute(aurweb.schema.RequestTypes.insert(), [
+        {'ID': 1, 'Name': 'deletion'},
+        {'ID': 2, 'Name': 'orphan'},
+        {'ID': 3, 'Name': 'merge'},
+    ])
+
+
+def run(args):
+    engine = sqlalchemy.create_engine(aurweb.db.get_sqlalchemy_url(),
+                                      echo=(args.verbose >= 1))
+    aurweb.schema.metadata.create_all(engine)
+    feed_initial_data(engine.connect())
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(
+        prog='python -m aurweb.initdb',
+        description='Initialize the aurweb database.')
+    parser.add_argument('-v', '--verbose', action='count', default=0,
+                        help='increase verbosity')
+    args = parser.parse_args()
+    run(args)