Update views.py

update to sqlalchemy 2.0

Author: Daniel-Faber

src/allocation/adapters/orm.py

@@ -1,25 +1,24 @@
 import logging
 from sqlalchemy import (
     Table,
-    MetaData,
     Column,
     Integer,
     String,
     Date,
     ForeignKey,
     event,
 )
-from sqlalchemy.orm import mapper, relationship
+from sqlalchemy.orm import registry, relationship
 
 from allocation.domain import model
 
 logger = logging.getLogger(__name__)
 
-metadata = MetaData()
+mapper_registry = registry()
 
 order_lines = Table(
     "order_lines",
-    metadata,
+    mapper_registry.metadata,
     Column("id", Integer, primary_key=True, autoincrement=True),
     Column("sku", String(255)),
     Column("qty", Integer, nullable=False),
@@ -28,14 +27,14 @@
 
 products = Table(
     "products",
-    metadata,
+    mapper_registry.metadata,
     Column("sku", String(255), primary_key=True),
     Column("version_number", Integer, nullable=False, server_default="0"),
 )
 
 batches = Table(
     "batches",
-    metadata,
+    mapper_registry.metadata,
     Column("id", Integer, primary_key=True, autoincrement=True),
     Column("reference", String(255)),
     Column("sku", ForeignKey("products.sku")),
@@ -45,15 +44,15 @@
 
 allocations = Table(
     "allocations",
-    metadata,
+    mapper_registry.metadata,
     Column("id", Integer, primary_key=True, autoincrement=True),
     Column("orderline_id", ForeignKey("order_lines.id")),
     Column("batch_id", ForeignKey("batches.id")),
 )
 
 allocations_view = Table(
     "allocations_view",
-    metadata,
+    mapper_registry.metadata,
     Column("orderid", String(255)),
     Column("sku", String(255)),
     Column("batchref", String(255)),
@@ -62,8 +61,8 @@
 
 def start_mappers():
     logger.info("Starting mappers")
-    lines_mapper = mapper(model.OrderLine, order_lines)
-    batches_mapper = mapper(
+    lines_mapper = mapper_registry.map_imperatively(model.OrderLine, order_lines)
+    batches_mapper = mapper_registry.map_imperatively(
         model.Batch,
         batches,
         properties={
@@ -74,7 +73,7 @@ def start_mappers():
             )
         },
     )
-    mapper(
+    mapper_registry.map_imperatively(
         model.Product,
         products,
         properties={"batches": relationship(batches_mapper)},

src/allocation/service_layer/handlers.py

@@ -4,6 +4,7 @@
 from typing import List, Dict, Callable, Type, TYPE_CHECKING
 from allocation.domain import commands, events, model
 from allocation.domain.model import OrderLine
+from sqlalchemy.sql import text
 
 if TYPE_CHECKING:
     from allocation.adapters import notifications
@@ -83,10 +84,10 @@ def add_allocation_to_read_model(
 ):
     with uow:
         uow.session.execute(
-            """
-            INSERT INTO allocations_view (orderid, sku, batchref)
-            VALUES (:orderid, :sku, :batchref)
-            """,
+            text(
+                "INSERT INTO allocations_view (orderid, sku, batchref)"
+                " VALUES (:orderid, :sku, :batchref)"
+            ),
             dict(orderid=event.orderid, sku=event.sku, batchref=event.batchref),
         )
         uow.commit()
@@ -98,10 +99,10 @@ def remove_allocation_from_read_model(
 ):
     with uow:
         uow.session.execute(
-            """
-            DELETE FROM allocations_view
-            WHERE orderid = :orderid AND sku = :sku
-            """,
+            text(
+                "DELETE FROM allocations_view"
+                " WHERE orderid = :orderid AND sku = :sku"
+            ),
             dict(orderid=event.orderid, sku=event.sku),
         )
         uow.commit()

src/allocation/views.py

@@ -1,12 +1,13 @@
 from allocation.service_layer import unit_of_work
+from sqlalchemy.sql import text
 
 
 def allocations(orderid: str, uow: unit_of_work.SqlAlchemyUnitOfWork):
     with uow:
         results = uow.session.execute(
-            """
-            SELECT sku, batchref FROM allocations_view WHERE orderid = :orderid
-            """,
+            text(
+                "SELECT sku, batchref FROM allocations_view WHERE orderid = :orderid"
+            ),
             dict(orderid=orderid),
         )
-    return [dict(r) for r in results]
+    return [r._asdict() for r in results]

tests/conftest.py

@@ -11,7 +11,7 @@
 from sqlalchemy.orm import sessionmaker, clear_mappers
 from tenacity import retry, stop_after_delay
 
-from allocation.adapters.orm import metadata, start_mappers
+from allocation.adapters.orm import mapper_registry, start_mappers
 from allocation import config
 
 pytest.register_assert_rewrite("tests.e2e.api_client")
@@ -20,7 +20,7 @@
 @pytest.fixture
 def in_memory_sqlite_db():
     engine = create_engine("sqlite:///:memory:")
-    metadata.create_all(engine)
+    mapper_registry.metadata.create_all(engine)
     return engine
 
 
@@ -56,7 +56,7 @@ def wait_for_redis_to_come_up():
 def postgres_db():
     engine = create_engine(config.get_postgres_uri(), isolation_level="SERIALIZABLE")
     wait_for_postgres_to_come_up(engine)
-    metadata.create_all(engine)
+    mapper_registry.metadata.create_all(engine)
     return engine
 
 

tests/integration/test_uow.py

@@ -8,30 +8,35 @@
 from allocation.domain import model
 from allocation.service_layer import unit_of_work
 from ..random_refs import random_sku, random_batchref, random_orderid
+from sqlalchemy.sql import text
 
 pytestmark = pytest.mark.usefixtures("mappers")
 
 
 def insert_batch(session, ref, sku, qty, eta, product_version=1):
     session.execute(
-        "INSERT INTO products (sku, version_number) VALUES (:sku, :version)",
+        text("INSERT INTO products (sku, version_number)" " VALUES (:sku, :version)"),
         dict(sku=sku, version=product_version),
     )
     session.execute(
-        "INSERT INTO batches (reference, sku, _purchased_quantity, eta)"
-        " VALUES (:ref, :sku, :qty, :eta)",
+        text(
+            "INSERT INTO batches (reference, sku, _purchased_quantity, eta)"
+            " VALUES (:ref, :sku, :qty, :eta)"
+        ),
         dict(ref=ref, sku=sku, qty=qty, eta=eta),
     )
 
 
 def get_allocated_batch_ref(session, orderid, sku):
     [[orderlineid]] = session.execute(
-        "SELECT id FROM order_lines WHERE orderid=:orderid AND sku=:sku",
+        text("SELECT id FROM order_lines WHERE orderid=:orderid AND sku=:sku"),
         dict(orderid=orderid, sku=sku),
     )
     [[batchref]] = session.execute(
-        "SELECT b.reference FROM allocations JOIN batches AS b ON batch_id = b.id"
-        " WHERE orderline_id=:orderlineid",
+        text(
+            "SELECT b.reference FROM allocations JOIN batches AS b ON batch_id = b.id"
+            " WHERE orderline_id=:orderlineid"
+        ),
         dict(orderlineid=orderlineid),
     )
     return batchref
@@ -59,7 +64,7 @@ def test_rolls_back_uncommitted_work_by_default(sqlite_session_factory):
         insert_batch(uow.session, "batch1", "MEDIUM-PLINTH", 100, None)
 
     new_session = sqlite_session_factory()
-    rows = list(new_session.execute('SELECT * FROM "batches"'))
+    rows = list(new_session.execute(text('SELECT * FROM "batches"')))
     assert rows == []
 
 
@@ -74,7 +79,7 @@ class MyException(Exception):
             raise MyException()
 
     new_session = sqlite_session_factory()
-    rows = list(new_session.execute('SELECT * FROM "batches"'))
+    rows = list(new_session.execute(text('SELECT * FROM "batches"')))
     assert rows == []
 
 
@@ -113,20 +118,22 @@ def test_concurrent_updates_to_version_are_not_allowed(postgres_session_factory)
     thread2.join()
 
     [[version]] = session.execute(
-        "SELECT version_number FROM products WHERE sku=:sku",
+        text("SELECT version_number FROM products WHERE sku=:sku"),
         dict(sku=sku),
     )
     assert version == 2
     [exception] = exceptions
     assert "could not serialize access due to concurrent update" in str(exception)
 
     orders = session.execute(
-        "SELECT orderid FROM allocations"
-        " JOIN batches ON allocations.batch_id = batches.id"
-        " JOIN order_lines ON allocations.orderline_id = order_lines.id"
-        " WHERE order_lines.sku=:sku",
+        text(
+            "SELECT orderid FROM allocations"
+            " JOIN batches ON allocations.batch_id = batches.id"
+            " JOIN order_lines ON allocations.orderline_id = order_lines.id"
+            " WHERE order_lines.sku=:sku"
+        ),
         dict(sku=sku),
     )
     assert orders.rowcount == 1
     with unit_of_work.SqlAlchemyUnitOfWork(postgres_session_factory) as uow:
-        uow.session.execute("select 1")
+        uow.session.execute(text("select 1"))