use declarative_base for all ORM models

This rewrites the entire model base as declarative models.
This allows us to more easily customize overlay fields
in tables and is more common.

This effort also brought some DB violations to light which
this commit addresses.

Signed-off-by: Kevin Morris <kevr@0cost.org>

aurweb/db.py

@@ -1,7 +1,5 @@
 import math
 
-from sqlalchemy.orm import backref, relationship
-
 import aurweb.config
 import aurweb.util
 
@@ -53,12 +51,6 @@ def make_random_value(table: str, column: str):
     return string
 
 
-def make_relationship(model, foreign_key: str, backref_: str, **kwargs):
-    return relationship(model, foreign_keys=[foreign_key],
-                        backref=backref(backref_, lazy="dynamic"),
-                        **kwargs)
-
-
 def query(model, *args, **kwargs):
     return session.query(model).filter(*args, **kwargs)
 
@@ -77,6 +69,10 @@ def delete(model, *args, **kwargs):
     session.commit()
 
 
+def rollback():
+    session.rollback()
+
+
 def get_sqlalchemy_url():
     """
     Build an SQLAlchemy for use with create_engine based on the aurweb configuration.
@@ -137,7 +133,6 @@ def get_engine(echo: bool = False):
             # check_same_thread is for a SQLite technicality
             # https://fastapi.tiangolo.com/tutorial/sql-databases/#note
             connect_args["check_same_thread"] = False
-
         engine = create_engine(get_sqlalchemy_url(),
                                connect_args=connect_args,
                                echo=echo)